1173 lines
90 KiB
Text
1173 lines
90 KiB
Text
<!DOCTYPE html>
|
||
<html lang="en" dir="ltr" prefix="content: http://purl.org/rss/1.0/modules/content/ dc: http://purl.org/dc/terms/ foaf: http://xmlns.com/foaf/0.1/ og: http://ogp.me/ns# rdfs: http://www.w3.org/2000/01/rdf-schema# schema: http://schema.org/ sioc: http://rdfs.org/sioc/ns# sioct: http://rdfs.org/sioc/types# skos: http://www.w3.org/2004/02/skos/core# xsd: http://www.w3.org/2001/XMLSchema# ">
|
||
<head>
|
||
<meta charset="utf-8" /><script type="text/javascript">(window.NREUM||(NREUM={})).init={ajax:{deny_list:["bam.nr-data.net"]}};(window.NREUM||(NREUM={})).loader_config={licenseKey:"37b7ccb661",applicationID:"1089704227"};;/*! For license information please see nr-loader-rum-1.283.2.min.js.LICENSE.txt */
|
||
(()=>{var e,t,r={122:(e,t,r)=>{"use strict";r.d(t,{a:()=>i});var n=r(944);function i(e,t){try{if(!e||"object"!=typeof e)return(0,n.R)(3);if(!t||"object"!=typeof t)return(0,n.R)(4);const r=Object.create(Object.getPrototypeOf(t),Object.getOwnPropertyDescriptors(t)),o=0===Object.keys(r).length?e:r;for(let a in o)if(void 0!==e[a])try{if(null===e[a]){r[a]=null;continue}Array.isArray(e[a])&&Array.isArray(t[a])?r[a]=Array.from(new Set([...e[a],...t[a]])):"object"==typeof e[a]&&"object"==typeof t[a]?r[a]=i(e[a],t[a]):r[a]=e[a]}catch(e){(0,n.R)(1,e)}return r}catch(e){(0,n.R)(2,e)}}},555:(e,t,r)=>{"use strict";r.d(t,{Vp:()=>c,fn:()=>s,x1:()=>u});var n=r(384),i=r(122);const o={beacon:n.NT.beacon,errorBeacon:n.NT.errorBeacon,licenseKey:void 0,applicationID:void 0,sa:void 0,queueTime:void 0,applicationTime:void 0,ttGuid:void 0,user:void 0,account:void 0,product:void 0,extra:void 0,jsAttributes:{},userAttributes:void 0,atts:void 0,transactionName:void 0,tNamePlain:void 0},a={};function s(e){try{const t=c(e);return!!t.licenseKey&&!!t.errorBeacon&&!!t.applicationID}catch(e){return!1}}function c(e){if(!e)throw new Error("All info objects require an agent identifier!");if(!a[e])throw new Error("Info for ".concat(e," was never set"));return a[e]}function u(e,t){if(!e)throw new Error("All info objects require an agent identifier!");a[e]=(0,i.a)(t,o);const r=(0,n.nY)(e);r&&(r.info=a[e])}},217:(e,t,r)=>{"use strict";r.d(t,{D0:()=>m,gD:()=>v,xN:()=>h});r(860).K7.genericEvents;const n="experimental.marks",i="experimental.measures",o="experimental.resources",a=e=>{if(!e||"string"!=typeof e)return!1;try{document.createDocumentFragment().querySelector(e)}catch{return!1}return!0};var s=r(614),c=r(944),u=r(384),l=r(122);const d="[data-nr-mask]",f=()=>{const e={feature_flags:[],experimental:{marks:!1,measures:!1,resources:!1},mask_selector:"*",block_selector:"[data-nr-block]",mask_input_options:{color:!1,date:!1,"datetime-local":!1,email:!1,month:!1,number:!1,range:!1,search:!1,tel:!1,text:!1,time:!1,url:!1,week:!1,textarea:!1,select:!1,password:!0}};return{ajax:{deny_list:void 0,block_internal:!0,enabled:!0,autoStart:!0},distributed_tracing:{enabled:void 0,exclude_newrelic_header:void 0,cors_use_newrelic_header:void 0,cors_use_tracecontext_headers:void 0,allowed_origins:void 0},get feature_flags(){return e.feature_flags},set feature_flags(t){e.feature_flags=t},generic_events:{enabled:!0,autoStart:!0},harvest:{interval:30},jserrors:{enabled:!0,autoStart:!0},logging:{enabled:!0,autoStart:!0},metrics:{enabled:!0,autoStart:!0},obfuscate:void 0,page_action:{enabled:!0},page_view_event:{enabled:!0,autoStart:!0},page_view_timing:{enabled:!0,autoStart:!0},performance:{get capture_marks(){return e.feature_flags.includes(n)||e.experimental.marks},set capture_marks(t){e.experimental.marks=t},get capture_measures(){return e.feature_flags.includes(i)||e.experimental.measures},set capture_measures(t){e.experimental.measures=t},capture_detail:!0,resources:{get enabled(){return e.feature_flags.includes(o)||e.experimental.resources},set enabled(t){e.experimental.resources=t},asset_types:[],first_party_domains:[],ignore_newrelic:!0}},privacy:{cookies_enabled:!0},proxy:{assets:void 0,beacon:void 0},session:{expiresMs:s.wk,inactiveMs:s.BB},session_replay:{autoStart:!0,enabled:!1,preload:!1,sampling_rate:10,error_sampling_rate:100,collect_fonts:!1,inline_images:!1,fix_stylesheets:!0,mask_all_inputs:!0,get mask_text_selector(){return e.mask_selector},set mask_text_selector(t){a(t)?e.mask_selector="".concat(t,",").concat(d):""===t||null===t?e.mask_selector=d:(0,c.R)(5,t)},get block_class(){return"nr-block"},get ignore_class(){return"nr-ignore"},get mask_text_class(){return"nr-mask"},get block_selector(){return e.block_selector},set block_selector(t){a(t)?e.block_selector+=",".concat(t):""!==t&&(0,c.R)(6,t)},get mask_input_options(){return e.mask_input_options},set mask_input_options(t){t&&"object"==typeof t?e.mask_input_options={...t,password:!0}:(0,c.R)(7,t)}},session_trace:{enabled:!0,autoStart:!0},soft_navigations:{enabled:!0,autoStart:!0},spa:{enabled:!0,autoStart:!0},ssl:void 0,user_actions:{enabled:!0,elementAttributes:["id","className","tagName","type"]}}},g={},p="All configuration objects require an agent identifier!";function m(e){if(!e)throw new Error(p);if(!g[e])throw new Error("Configuration for ".concat(e," was never set"));return g[e]}function h(e,t){if(!e)throw new Error(p);g[e]=(0,l.a)(t,f());const r=(0,u.nY)(e);r&&(r.init=g[e])}function v(e,t){if(!e)throw new Error(p);var r=m(e);if(r){for(var n=t.split("."),i=0;i<n.length-1;i++)if("object"!=typeof(r=r[n[i]]))return;r=r[n[n.length-1]]}return r}},371:(e,t,r)=>{"use strict";r.d(t,{V:()=>f,f:()=>d});var n=r(122),i=r(384),o=r(154),a=r(324);let s=0;const c={buildEnv:a.F3,distMethod:a.Xs,version:a.xv,originTime:o.WN},u={customTransaction:void 0,disabled:!1,isolatedBacklog:!1,loaderType:void 0,maxBytes:3e4,onerror:void 0,ptid:void 0,releaseIds:{},appMetadata:{},session:void 0,denyList:void 0,timeKeeper:void 0,obfuscator:void 0,harvester:void 0},l={};function d(e){if(!e)throw new Error("All runtime objects require an agent identifier!");if(!l[e])throw new Error("Runtime for ".concat(e," was never set"));return l[e]}function f(e,t){if(!e)throw new Error("All runtime objects require an agent identifier!");l[e]={...(0,n.a)(t,u),...c},Object.hasOwnProperty.call(l[e],"harvestCount")||Object.defineProperty(l[e],"harvestCount",{get:()=>++s});const r=(0,i.nY)(e);r&&(r.runtime=l[e])}},324:(e,t,r)=>{"use strict";r.d(t,{F3:()=>i,Xs:()=>o,xv:()=>n});const n="1.283.2",i="PROD",o="CDN"},154:(e,t,r)=>{"use strict";r.d(t,{OF:()=>c,RI:()=>i,WN:()=>l,bv:()=>o,gm:()=>a,mw:()=>s,sb:()=>u});var n=r(863);const i="undefined"!=typeof window&&!!window.document,o="undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self.navigator instanceof WorkerNavigator||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis.navigator instanceof WorkerNavigator),a=i?window:"undefined"!=typeof WorkerGlobalScope&&("undefined"!=typeof self&&self instanceof WorkerGlobalScope&&self||"undefined"!=typeof globalThis&&globalThis instanceof WorkerGlobalScope&&globalThis),s=Boolean("hidden"===a?.document?.visibilityState),c=/iPad|iPhone|iPod/.test(a.navigator?.userAgent),u=c&&"undefined"==typeof SharedWorker,l=((()=>{const e=a.navigator?.userAgent?.match(/Firefox[/\s](\d+\.\d+)/);Array.isArray(e)&&e.length>=2&&e[1]})(),Date.now()-(0,n.t)())},687:(e,t,r)=>{"use strict";r.d(t,{Ak:()=>c,Ze:()=>d,x3:()=>u});var n=r(836),i=r(606),o=r(860),a=r(646);const s={};function c(e,t){const r={staged:!1,priority:o.P3[t]||0};l(e),s[e].get(t)||s[e].set(t,r)}function u(e,t){e&&s[e]&&(s[e].get(t)&&s[e].delete(t),g(e,t,!1),s[e].size&&f(e))}function l(e){if(!e)throw new Error("agentIdentifier required");s[e]||(s[e]=new Map)}function d(e="",t="feature",r=!1){if(l(e),!e||!s[e].get(t)||r)return g(e,t);s[e].get(t).staged=!0,f(e)}function f(e){const t=Array.from(s[e]);t.every((([e,t])=>t.staged))&&(t.sort(((e,t)=>e[1].priority-t[1].priority)),t.forEach((([t])=>{s[e].delete(t),g(e,t)})))}function g(e,t,r=!0){const o=e?n.ee.get(e):n.ee,s=i.i.handlers;if(!o.aborted&&o.backlog&&s){if(r){const e=o.backlog[t],r=s[t];if(r){for(let t=0;e&&t<e.length;++t)p(e[t],r);Object.entries(r).forEach((([e,t])=>{Object.values(t||{}).forEach((t=>{t[0]?.on&&t[0]?.context()instanceof a.y&&t[0].on(e,t[1])}))}))}}o.isolatedBacklog||delete s[t],o.backlog[t]=null,o.emit("drain-"+t,[])}}function p(e,t){var r=e[1];Object.values(t[r]||{}).forEach((t=>{var r=e[0];if(t[0]===r){var n=t[1],i=e[3],o=e[2];n.apply(i,o)}}))}},836:(e,t,r)=>{"use strict";r.d(t,{P:()=>c,ee:()=>u});var n=r(384),i=r(990),o=r(371),a=r(646),s=r(607);const c="nr@context:".concat(s.W),u=function e(t,r){var n={},s={},l={},d=!1;try{d=16===r.length&&(0,o.f)(r).isolatedBacklog}catch(e){}var f={on:p,addEventListener:p,removeEventListener:function(e,t){var r=n[e];if(!r)return;for(var i=0;i<r.length;i++)r[i]===t&&r.splice(i,1)},emit:function(e,r,n,i,o){!1!==o&&(o=!0);if(u.aborted&&!i)return;t&&o&&t.emit(e,r,n);for(var a=g(n),c=m(e),l=c.length,d=0;d<l;d++)c[d].apply(a,r);var p=v()[s[e]];p&&p.push([f,e,r,a]);return a},get:h,listeners:m,context:g,buffer:function(e,t){const r=v();if(t=t||"feature",f.aborted)return;Object.entries(e||{}).forEach((([e,n])=>{s[n]=t,t in r||(r[t]=[])}))},abort:function(){f._aborted=!0,Object.keys(f.backlog).forEach((e=>{delete f.backlog[e]}))},isBuffering:function(e){return!!v()[s[e]]},debugId:r,backlog:d?{}:t&&"object"==typeof t.backlog?t.backlog:{},isolatedBacklog:d};return Object.defineProperty(f,"aborted",{get:()=>{let e=f._aborted||!1;return e||(t&&(e=t.aborted),e)}}),f;function g(e){return e&&e instanceof a.y?e:e?(0,i.I)(e,c,(()=>new a.y(c))):new a.y(c)}function p(e,t){n[e]=m(e).concat(t)}function m(e){return n[e]||[]}function h(t){return l[t]=l[t]||e(f,t)}function v(){return f.backlog}}(void 0,"globalEE"),l=(0,n.Zm)();l.ee||(l.ee=u)},646:(e,t,r)=>{"use strict";r.d(t,{y:()=>n});class n{constructor(e){this.contextId=e}}},908:(e,t,r)=>{"use strict";r.d(t,{d:()=>n,p:()=>i});var n=r(836).ee.get("handle");function i(e,t,r,i,o){o?(o.buffer([e],i),o.emit(e,t,r)):(n.buffer([e],i),n.emit(e,t,r))}},606:(e,t,r)=>{"use strict";r.d(t,{i:()=>o});var n=r(908);o.on=a;var i=o.handlers={};function o(e,t,r,o){a(o||n.d,i,e,t,r)}function a(e,t,r,i,o){o||(o="feature"),e||(e=n.d);var a=t[o]=t[o]||{};(a[r]=a[r]||[]).push([e,i])}},878:(e,t,r)=>{"use strict";function n(e,t){return{capture:e,passive:!1,signal:t}}function i(e,t,r=!1,i){window.addEventListener(e,t,n(r,i))}function o(e,t,r=!1,i){document.addEventListener(e,t,n(r,i))}r.d(t,{DD:()=>o,jT:()=>n,sp:()=>i})},607:(e,t,r)=>{"use strict";r.d(t,{W:()=>n});const n=(0,r(566).bz)()},566:(e,t,r)=>{"use strict";r.d(t,{LA:()=>s,bz:()=>a});var n=r(154);const i="xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx";function o(e,t){return e?15&e[t]:16*Math.random()|0}function a(){const e=n.gm?.crypto||n.gm?.msCrypto;let t,r=0;return e&&e.getRandomValues&&(t=e.getRandomValues(new Uint8Array(30))),i.split("").map((e=>"x"===e?o(t,r++).toString(16):"y"===e?(3&o()|8).toString(16):e)).join("")}function s(e){const t=n.gm?.crypto||n.gm?.msCrypto;let r,i=0;t&&t.getRandomValues&&(r=t.getRandomValues(new Uint8Array(e)));const a=[];for(var s=0;s<e;s++)a.push(o(r,i++).toString(16));return a.join("")}},614:(e,t,r)=>{"use strict";r.d(t,{BB:()=>a,H3:()=>n,g:()=>u,iL:()=>c,tS:()=>s,uh:()=>i,wk:()=>o});const n="NRBA",i="SESSION",o=144e5,a=18e5,s={STARTED:"session-started",PAUSE:"session-pause",RESET:"session-reset",RESUME:"session-resume",UPDATE:"session-update"},c={SAME_TAB:"same-tab",CROSS_TAB:"cross-tab"},u={OFF:0,FULL:1,ERROR:2}},863:(e,t,r)=>{"use strict";function n(){return Math.floor(performance.now())}r.d(t,{t:()=>n})},944:(e,t,r)=>{"use strict";function n(e,t){"function"==typeof console.debug&&console.debug("New Relic Warning: https://github.com/newrelic/newrelic-browser-agent/blob/main/docs/warning-codes.md#".concat(e),t)}r.d(t,{R:()=>n})},284:(e,t,r)=>{"use strict";r.d(t,{t:()=>c,B:()=>s});var n=r(836),i=r(154);const o="newrelic";const a=new Set,s={};function c(e,t){const r=n.ee.get(t);s[t]??={},e&&"object"==typeof e&&(a.has(t)||(r.emit("rumresp",[e]),s[t]=e,a.add(t),function(e={}){try{i.gm.dispatchEvent(new CustomEvent(o,{detail:e}))}catch(e){}}({loaded:!0})))}},990:(e,t,r)=>{"use strict";r.d(t,{I:()=>i});var n=Object.prototype.hasOwnProperty;function i(e,t,r){if(n.call(e,t))return e[t];var i=r();if(Object.defineProperty&&Object.keys)try{return Object.defineProperty(e,t,{value:i,writable:!0,enumerable:!1}),i}catch(e){}return e[t]=i,i}},389:(e,t,r)=>{"use strict";function n(e,t=500,r={}){const n=r?.leading||!1;let i;return(...r)=>{n&&void 0===i&&(e.apply(this,r),i=setTimeout((()=>{i=clearTimeout(i)}),t)),n||(clearTimeout(i),i=setTimeout((()=>{e.apply(this,r)}),t))}}function i(e){let t=!1;return(...r)=>{t||(t=!0,e.apply(this,r))}}r.d(t,{J:()=>i,s:()=>n})},289:(e,t,r)=>{"use strict";r.d(t,{GG:()=>o,sB:()=>a});var n=r(878);function i(){return"undefined"==typeof document||"complete"===document.readyState}function o(e,t){if(i())return e();(0,n.sp)("load",e,t)}function a(e){if(i())return e();(0,n.DD)("DOMContentLoaded",e)}},384:(e,t,r)=>{"use strict";r.d(t,{NT:()=>o,US:()=>l,Zm:()=>a,bQ:()=>c,dV:()=>s,nY:()=>u,pV:()=>d});var n=r(154),i=r(863);const o={beacon:"bam.nr-data.net",errorBeacon:"bam.nr-data.net"};function a(){return n.gm.NREUM||(n.gm.NREUM={}),void 0===n.gm.newrelic&&(n.gm.newrelic=n.gm.NREUM),n.gm.NREUM}function s(){let e=a();return e.o||(e.o={ST:n.gm.setTimeout,SI:n.gm.setImmediate,CT:n.gm.clearTimeout,XHR:n.gm.XMLHttpRequest,REQ:n.gm.Request,EV:n.gm.Event,PR:n.gm.Promise,MO:n.gm.MutationObserver,FETCH:n.gm.fetch,WS:n.gm.WebSocket}),e}function c(e,t){let r=a();r.initializedAgents??={},t.initializedAt={ms:(0,i.t)(),date:new Date},r.initializedAgents[e]=t}function u(e){let t=a();return t.initializedAgents?.[e]}function l(e,t){a()[e]=t}function d(){return function(){let e=a();const t=e.info||{};e.info={beacon:o.beacon,errorBeacon:o.errorBeacon,...t}}(),function(){let e=a();const t=e.init||{};e.init={...t}}(),s(),function(){let e=a();const t=e.loader_config||{};e.loader_config={...t}}(),a()}},843:(e,t,r)=>{"use strict";r.d(t,{u:()=>i});var n=r(878);function i(e,t=!1,r,i){(0,n.DD)("visibilitychange",(function(){if(t)return void("hidden"===document.visibilityState&&e());e(document.visibilityState)}),r,i)}},434:(e,t,r)=>{"use strict";r.d(t,{Jt:()=>o,YM:()=>c});var n=r(836),i=r(607);const o="nr@original:".concat(i.W);var a=Object.prototype.hasOwnProperty,s=!1;function c(e,t){return e||(e=n.ee),r.inPlace=function(e,t,n,i,o){n||(n="");const a="-"===n.charAt(0);for(let s=0;s<t.length;s++){const c=t[s],u=e[c];l(u)||(e[c]=r(u,a?c+n:n,i,c,o))}},r.flag=o,r;function r(t,r,n,s,c){return l(t)?t:(r||(r=""),nrWrapper[o]=t,function(e,t,r){if(Object.defineProperty&&Object.keys)try{return Object.keys(e).forEach((function(r){Object.defineProperty(t,r,{get:function(){return e[r]},set:function(t){return e[r]=t,t}})})),t}catch(e){u([e],r)}for(var n in e)a.call(e,n)&&(t[n]=e[n])}(t,nrWrapper,e),nrWrapper);function nrWrapper(){var o,a,l,d;try{a=this,o=[...arguments],l="function"==typeof n?n(o,a):n||{}}catch(t){u([t,"",[o,a,s],l],e)}i(r+"start",[o,a,s],l,c);try{return d=t.apply(a,o)}catch(e){throw i(r+"err",[o,a,e],l,c),e}finally{i(r+"end",[o,a,d],l,c)}}}function i(r,n,i,o){if(!s||t){var a=s;s=!0;try{e.emit(r,n,i,t,o)}catch(t){u([t,r,n,i],e)}s=a}}}function u(e,t){t||(t=n.ee);try{t.emit("internal-error",e)}catch(e){}}function l(e){return!(e&&"function"==typeof e&&e.apply&&!e[o])}},993:(e,t,r)=>{"use strict";r.d(t,{A$:()=>o,ET:()=>a,p_:()=>i});var n=r(860);const i={ERROR:"ERROR",WARN:"WARN",INFO:"INFO",DEBUG:"DEBUG",TRACE:"TRACE"},o={OFF:0,ERROR:1,WARN:2,INFO:3,DEBUG:4,TRACE:5},a="log";n.K7.logging},773:(e,t,r)=>{"use strict";r.d(t,{z_:()=>o,XG:()=>s,TZ:()=>n,rs:()=>i,xV:()=>a});r(154),r(566),r(384);const n=r(860).K7.metrics,i="sm",o="cm",a="storeSupportabilityMetrics",s="storeEventMetrics"},630:(e,t,r)=>{"use strict";r.d(t,{T:()=>n});const n=r(860).K7.pageViewEvent},782:(e,t,r)=>{"use strict";r.d(t,{T:()=>n});const n=r(860).K7.pageViewTiming},344:(e,t,r)=>{"use strict";r.d(t,{G4:()=>i});var n=r(614);r(860).K7.sessionReplay;const i={RECORD:"recordReplay",PAUSE:"pauseReplay",REPLAY_RUNNING:"replayRunning",ERROR_DURING_REPLAY:"errorDuringReplay"};n.g.ERROR,n.g.FULL,n.g.OFF},234:(e,t,r)=>{"use strict";r.d(t,{W:()=>o});var n=r(836),i=r(687);class o{constructor(e,t){this.agentIdentifier=e,this.ee=n.ee.get(e),this.featureName=t,this.blocked=!1}deregisterDrain(){(0,i.x3)(this.agentIdentifier,this.featureName)}}},603:(e,t,r)=>{"use strict";r.d(t,{j:()=>K});var n=r(860),i=r(555),o=r(371),a=r(908),s=r(836),c=r(687),u=r(289),l=r(154),d=r(944),f=r(773),g=r(384),p=r(344);const m=["setErrorHandler","finished","addToTrace","addRelease","recordCustomEvent","addPageAction","setCurrentRouteName","setPageViewName","setCustomAttribute","interaction","noticeError","setUserId","setApplicationVersion","start",p.G4.RECORD,p.G4.PAUSE,"log","wrapLogger"],h=["setErrorHandler","finished","addToTrace","addRelease"];var v=r(863),b=r(614),y=r(993);var w=r(646),R=r(434);const A=new Map;function E(e,t,r,n){if("object"!=typeof t||!t||"string"!=typeof r||!r||"function"!=typeof t[r])return(0,d.R)(29);const i=function(e){return(e||s.ee).get("logger")}(e),o=(0,R.YM)(i),a=new w.y(s.P);a.level=n.level,a.customAttributes=n.customAttributes;const c=t[r]?.[R.Jt]||t[r];return A.set(c,a),o.inPlace(t,[r],"wrap-logger-",(()=>A.get(c))),i}function _(){const e=(0,g.pV)();m.forEach((t=>{e[t]=(...r)=>function(t,...r){let n=[];return Object.values(e.initializedAgents).forEach((e=>{e&&e.api?e.exposed&&e.api[t]&&n.push(e.api[t](...r)):(0,d.R)(38,t)})),n.length>1?n:n[0]}(t,...r)}))}const x={};function N(e,t,g=!1){t||(0,c.Ak)(e,"api");const m={};var w=s.ee.get(e),R=w.get("tracer");x[e]=b.g.OFF,w.on(p.G4.REPLAY_RUNNING,(t=>{x[e]=t}));var A="api-",_=A+"ixn-";function N(t,r,n,o){const a=(0,i.Vp)(e);return null===r?delete a.jsAttributes[t]:(0,i.x1)(e,{...a,jsAttributes:{...a.jsAttributes,[t]:r}}),j(A,n,!0,o||null===r?"session":void 0)(t,r)}function k(){}m.log=function(e,{customAttributes:t={},level:r=y.p_.INFO}={}){(0,a.p)(f.xV,["API/log/called"],void 0,n.K7.metrics,w),function(e,t,r={},i=y.p_.INFO){(0,a.p)(f.xV,["API/logging/".concat(i.toLowerCase(),"/called")],void 0,n.K7.metrics,e),(0,a.p)(y.ET,[(0,v.t)(),t,r,i],void 0,n.K7.logging,e)}(w,e,t,r)},m.wrapLogger=(e,t,{customAttributes:r={},level:i=y.p_.INFO}={})=>{(0,a.p)(f.xV,["API/wrapLogger/called"],void 0,n.K7.metrics,w),E(w,e,t,{customAttributes:r,level:i})},h.forEach((e=>{m[e]=j(A,e,!0,"api")})),m.addPageAction=j(A,"addPageAction",!0,n.K7.genericEvents),m.recordCustomEvent=j(A,"recordCustomEvent",!0,n.K7.genericEvents),m.setPageViewName=function(t,r){if("string"==typeof t)return"/"!==t.charAt(0)&&(t="/"+t),(0,o.f)(e).customTransaction=(r||"http://custom.transaction")+t,j(A,"setPageViewName",!0)()},m.setCustomAttribute=function(e,t,r=!1){if("string"==typeof e){if(["string","number","boolean"].includes(typeof t)||null===t)return N(e,t,"setCustomAttribute",r);(0,d.R)(40,typeof t)}else(0,d.R)(39,typeof e)},m.setUserId=function(e){if("string"==typeof e||null===e)return N("enduser.id",e,"setUserId",!0);(0,d.R)(41,typeof e)},m.setApplicationVersion=function(e){if("string"==typeof e||null===e)return N("application.version",e,"setApplicationVersion",!1);(0,d.R)(42,typeof e)},m.start=()=>{try{(0,a.p)(f.xV,["API/start/called"],void 0,n.K7.metrics,w),w.emit("manual-start-all")}catch(e){(0,d.R)(23,e)}},m[p.G4.RECORD]=function(){(0,a.p)(f.xV,["API/recordReplay/called"],void 0,n.K7.metrics,w),(0,a.p)(p.G4.RECORD,[],void 0,n.K7.sessionReplay,w)},m[p.G4.PAUSE]=function(){(0,a.p)(f.xV,["API/pauseReplay/called"],void 0,n.K7.metrics,w),(0,a.p)(p.G4.PAUSE,[],void 0,n.K7.sessionReplay,w)},m.interaction=function(e){return(new k).get("object"==typeof e?e:{})};const T=k.prototype={createTracer:function(e,t){var r={},i=this,o="function"==typeof t;return(0,a.p)(f.xV,["API/createTracer/called"],void 0,n.K7.metrics,w),g||(0,a.p)(_+"tracer",[(0,v.t)(),e,r],i,n.K7.spa,w),function(){if(R.emit((o?"":"no-")+"fn-start",[(0,v.t)(),i,o],r),o)try{return t.apply(this,arguments)}catch(e){const t="string"==typeof e?new Error(e):e;throw R.emit("fn-err",[arguments,this,t],r),t}finally{R.emit("fn-end",[(0,v.t)()],r)}}}};function j(e,t,r,i){return function(){return(0,a.p)(f.xV,["API/"+t+"/called"],void 0,n.K7.metrics,w),i&&(0,a.p)(e+t,[r?(0,v.t)():performance.now(),...arguments],r?null:this,i,w),r?void 0:this}}function I(){r.e(296).then(r.bind(r,778)).then((({setAPI:t})=>{t(e),(0,c.Ze)(e,"api")})).catch((e=>{(0,d.R)(27,e),w.abort()}))}return["actionText","setName","setAttribute","save","ignore","onEnd","getContext","end","get"].forEach((e=>{T[e]=j(_,e,void 0,g?n.K7.softNav:n.K7.spa)})),m.setCurrentRouteName=g?j(_,"routeName",void 0,n.K7.softNav):j(A,"routeName",!0,n.K7.spa),m.noticeError=function(t,r){"string"==typeof t&&(t=new Error(t)),(0,a.p)(f.xV,["API/noticeError/called"],void 0,n.K7.metrics,w),(0,a.p)("err",[t,(0,v.t)(),!1,r,!!x[e]],void 0,n.K7.jserrors,w)},l.RI?(0,u.GG)((()=>I()),!0):I(),m}var k=r(217),T=r(122);const j={accountID:void 0,trustKey:void 0,agentID:void 0,licenseKey:void 0,applicationID:void 0,xpid:void 0},I={};var O=r(284);const S=e=>{const t=e.startsWith("http");e+="/",r.p=t?e:"https://"+e};let P=!1;function K(e,t={},r,n){let{init:a,info:c,loader_config:u,runtime:d={},exposed:f=!0}=t;d.loaderType=r;const p=(0,g.pV)();c||(a=p.init,c=p.info,u=p.loader_config),(0,k.xN)(e.agentIdentifier,a||{}),function(e,t){if(!e)throw new Error("All loader-config objects require an agent identifier!");I[e]=(0,T.a)(t,j);const r=(0,g.nY)(e);r&&(r.loader_config=I[e])}(e.agentIdentifier,u||{}),c.jsAttributes??={},l.bv&&(c.jsAttributes.isWorker=!0),(0,i.x1)(e.agentIdentifier,c);const m=(0,k.D0)(e.agentIdentifier),h=[c.beacon,c.errorBeacon];P||(m.proxy.assets&&(S(m.proxy.assets),h.push(m.proxy.assets)),m.proxy.beacon&&h.push(m.proxy.beacon),_(),(0,g.US)("activatedFeatures",O.B),e.runSoftNavOverSpa&&=!0===m.soft_navigations.enabled&&m.feature_flags.includes("soft_nav")),d.denyList=[...m.ajax.deny_list||[],...m.ajax.block_internal?h:[]],d.ptid=e.agentIdentifier,(0,o.V)(e.agentIdentifier,d),e.ee=s.ee.get(e.agentIdentifier),void 0===e.api&&(e.api=N(e.agentIdentifier,n,e.runSoftNavOverSpa)),void 0===e.exposed&&(e.exposed=f),P=!0}},374:(e,t,r)=>{r.nc=(()=>{try{return document?.currentScript?.nonce}catch(e){}return""})()},860:(e,t,r)=>{"use strict";r.d(t,{$J:()=>u,K7:()=>s,P3:()=>c,XX:()=>i,qY:()=>n,v4:()=>a});const n="events",i="jserrors",o="browser/blobs",a="rum",s={ajax:"ajax",genericEvents:"generic_events",jserrors:i,logging:"logging",metrics:"metrics",pageAction:"page_action",pageViewEvent:"page_view_event",pageViewTiming:"page_view_timing",sessionReplay:"session_replay",sessionTrace:"session_trace",softNav:"soft_navigations",spa:"spa"},c={[s.pageViewEvent]:1,[s.pageViewTiming]:2,[s.metrics]:3,[s.jserrors]:4,[s.spa]:5,[s.ajax]:6,[s.sessionTrace]:7,[s.softNav]:8,[s.sessionReplay]:9,[s.logging]:10,[s.genericEvents]:11},u={[s.pageViewEvent]:a,[s.pageViewTiming]:n,[s.ajax]:n,[s.spa]:n,[s.softNav]:n,[s.metrics]:i,[s.jserrors]:i,[s.sessionTrace]:o,[s.sessionReplay]:o,[s.logging]:"browser/logs",[s.genericEvents]:"ins"}}},n={};function i(e){var t=n[e];if(void 0!==t)return t.exports;var o=n[e]={exports:{}};return r[e](o,o.exports,i),o.exports}i.m=r,i.d=(e,t)=>{for(var r in t)i.o(t,r)&&!i.o(e,r)&&Object.defineProperty(e,r,{enumerable:!0,get:t[r]})},i.f={},i.e=e=>Promise.all(Object.keys(i.f).reduce(((t,r)=>(i.f[r](e,t),t)),[])),i.u=e=>"nr-rum-1.283.2.min.js",i.o=(e,t)=>Object.prototype.hasOwnProperty.call(e,t),e={},t="NRBA-1.283.2.PROD:",i.l=(r,n,o,a)=>{if(e[r])e[r].push(n);else{var s,c;if(void 0!==o)for(var u=document.getElementsByTagName("script"),l=0;l<u.length;l++){var d=u[l];if(d.getAttribute("src")==r||d.getAttribute("data-webpack")==t+o){s=d;break}}if(!s){c=!0;var f={296:"sha512-2Y8GMAOGF658KnXzOZ/v+DlLch8TBFvV0tTNnOy9wrpvtDa1t5CdZMyX+LubTymBlzPp6NUjllBghMCZqXBPmg=="};(s=document.createElement("script")).charset="utf-8",s.timeout=120,i.nc&&s.setAttribute("nonce",i.nc),s.setAttribute("data-webpack",t+o),s.src=r,0!==s.src.indexOf(window.location.origin+"/")&&(s.crossOrigin="anonymous"),f[a]&&(s.integrity=f[a])}e[r]=[n];var g=(t,n)=>{s.onerror=s.onload=null,clearTimeout(p);var i=e[r];if(delete e[r],s.parentNode&&s.parentNode.removeChild(s),i&&i.forEach((e=>e(n))),t)return t(n)},p=setTimeout(g.bind(null,void 0,{type:"timeout",target:s}),12e4);s.onerror=g.bind(null,s.onerror),s.onload=g.bind(null,s.onload),c&&document.head.appendChild(s)}},i.r=e=>{"undefined"!=typeof Symbol&&Symbol.toStringTag&&Object.defineProperty(e,Symbol.toStringTag,{value:"Module"}),Object.defineProperty(e,"__esModule",{value:!0})},i.p="https://js-agent.newrelic.com/",(()=>{var e={374:0,840:0};i.f.j=(t,r)=>{var n=i.o(e,t)?e[t]:void 0;if(0!==n)if(n)r.push(n[2]);else{var o=new Promise(((r,i)=>n=e[t]=[r,i]));r.push(n[2]=o);var a=i.p+i.u(t),s=new Error;i.l(a,(r=>{if(i.o(e,t)&&(0!==(n=e[t])&&(e[t]=void 0),n)){var o=r&&("load"===r.type?"missing":r.type),a=r&&r.target&&r.target.src;s.message="Loading chunk "+t+" failed.\n("+o+": "+a+")",s.name="ChunkLoadError",s.type=o,s.request=a,n[1](s)}}),"chunk-"+t,t)}};var t=(t,r)=>{var n,o,[a,s,c]=r,u=0;if(a.some((t=>0!==e[t]))){for(n in s)i.o(s,n)&&(i.m[n]=s[n]);if(c)c(i)}for(t&&t(r);u<a.length;u++)o=a[u],i.o(e,o)&&e[o]&&e[o][0](),e[o]=0},r=self["webpackChunk:NRBA-1.283.2.PROD"]=self["webpackChunk:NRBA-1.283.2.PROD"]||[];r.forEach(t.bind(null,0)),r.push=t.bind(null,r.push.bind(r))})(),(()=>{"use strict";i(374);var e=i(944),t=i(344),r=i(566);class n{agentIdentifier;constructor(){this.agentIdentifier=(0,r.LA)(16)}#e(t,...r){if("function"==typeof this.api?.[t])return this.api[t](...r);(0,e.R)(35,t)}addPageAction(e,t){return this.#e("addPageAction",e,t)}recordCustomEvent(e,t){return this.#e("recordCustomEvent",e,t)}setPageViewName(e,t){return this.#e("setPageViewName",e,t)}setCustomAttribute(e,t,r){return this.#e("setCustomAttribute",e,t,r)}noticeError(e,t){return this.#e("noticeError",e,t)}setUserId(e){return this.#e("setUserId",e)}setApplicationVersion(e){return this.#e("setApplicationVersion",e)}setErrorHandler(e){return this.#e("setErrorHandler",e)}addRelease(e,t){return this.#e("addRelease",e,t)}log(e,t){return this.#e("log",e,t)}}class o extends n{#e(t,...r){if("function"==typeof this.api?.[t])return this.api[t](...r);(0,e.R)(35,t)}start(){return this.#e("start")}finished(e){return this.#e("finished",e)}recordReplay(){return this.#e(t.G4.RECORD)}pauseReplay(){return this.#e(t.G4.PAUSE)}addToTrace(e){return this.#e("addToTrace",e)}setCurrentRouteName(e){return this.#e("setCurrentRouteName",e)}interaction(){return this.#e("interaction")}wrapLogger(e,t,r){return this.#e("wrapLogger",e,t,r)}}var a=i(860),s=i(217);const c=Object.values(a.K7);function u(e){const t={};return c.forEach((r=>{t[r]=function(e,t){return!0===(0,s.gD)(t,"".concat(e,".enabled"))}(r,e)})),t}var l=i(603);var d=i(687),f=i(234),g=i(289),p=i(154),m=i(384);const h=e=>p.RI&&!0===(0,s.gD)(e,"privacy.cookies_enabled");function v(e){return!!(0,m.dV)().o.MO&&h(e)&&!0===(0,s.gD)(e,"session_trace.enabled")}var b=i(389);class y extends f.W{constructor(e,t,r=!0){super(e.agentIdentifier,t),this.auto=r,this.abortHandler=void 0,this.featAggregate=void 0,this.onAggregateImported=void 0,!1===e.init[this.featureName].autoStart&&(this.auto=!1),this.auto?(0,d.Ak)(e.agentIdentifier,t):this.ee.on("manual-start-all",(0,b.J)((()=>{(0,d.Ak)(e.agentIdentifier,this.featureName),this.auto=!0,this.importAggregator(e)})))}importAggregator(t,r={}){if(this.featAggregate||!this.auto)return;let n;this.onAggregateImported=new Promise((e=>{n=e}));const o=async()=>{let o;try{if(h(this.agentIdentifier)){const{setupAgentSession:e}=await i.e(296).then(i.bind(i,861));o=e(t)}}catch(t){(0,e.R)(20,t),this.ee.emit("internal-error",[t]),this.featureName===a.K7.sessionReplay&&this.abortHandler?.()}try{if(!this.#t(this.featureName,o))return(0,d.Ze)(this.agentIdentifier,this.featureName),void n(!1);const{lazyFeatureLoader:e}=await i.e(296).then(i.bind(i,103)),{Aggregate:a}=await e(this.featureName,"aggregate");this.featAggregate=new a(t,r),t.runtime.harvester.initializedAggregates.push(this.featAggregate),n(!0)}catch(t){(0,e.R)(34,t),this.abortHandler?.(),(0,d.Ze)(this.agentIdentifier,this.featureName,!0),n(!1),this.ee&&this.ee.abort()}};p.RI?(0,g.GG)((()=>o()),!0):o()}#t(e,t){switch(e){case a.K7.sessionReplay:return v(this.agentIdentifier)&&!!t;case a.K7.sessionTrace:return!!t;default:return!0}}}var w=i(630);class R extends y{static featureName=w.T;constructor(e,t=!0){super(e,w.T,t),this.importAggregator(e)}}var A=i(908),E=i(843),_=i(878),x=i(782),N=i(863);class k extends y{static featureName=x.T;constructor(e,t=!0){super(e,x.T,t),p.RI&&((0,E.u)((()=>(0,A.p)("docHidden",[(0,N.t)()],void 0,x.T,this.ee)),!0),(0,_.sp)("pagehide",(()=>(0,A.p)("winPagehide",[(0,N.t)()],void 0,x.T,this.ee))),this.importAggregator(e))}}var T=i(773);class j extends y{static featureName=T.TZ;constructor(e,t=!0){super(e,T.TZ,t),this.importAggregator(e)}}new class extends o{constructor(t){super(),p.gm?(this.features={},(0,m.bQ)(this.agentIdentifier,this),this.desiredFeatures=new Set(t.features||[]),this.desiredFeatures.add(R),this.runSoftNavOverSpa=[...this.desiredFeatures].some((e=>e.featureName===a.K7.softNav)),(0,l.j)(this,t,t.loaderType||"agent"),this.run()):(0,e.R)(21)}get config(){return{info:this.info,init:this.init,loader_config:this.loader_config,runtime:this.runtime}}run(){try{const t=u(this.agentIdentifier),r=[...this.desiredFeatures];r.sort(((e,t)=>a.P3[e.featureName]-a.P3[t.featureName])),r.forEach((r=>{if(!t[r.featureName]&&r.featureName!==a.K7.pageViewEvent)return;if(this.runSoftNavOverSpa&&r.featureName===a.K7.spa)return;if(!this.runSoftNavOverSpa&&r.featureName===a.K7.softNav)return;const n=function(e){switch(e){case a.K7.ajax:return[a.K7.jserrors];case a.K7.sessionTrace:return[a.K7.ajax,a.K7.pageViewEvent];case a.K7.sessionReplay:return[a.K7.sessionTrace];case a.K7.pageViewTiming:return[a.K7.pageViewEvent];default:return[]}}(r.featureName).filter((e=>!(e in this.features)));n.length>0&&(0,e.R)(36,{targetFeature:r.featureName,missingDependencies:n}),this.features[r.featureName]=new r(this)}))}catch(t){(0,e.R)(22,t);for(const e in this.features)this.features[e].abortHandler?.();const r=(0,m.Zm)();delete r.initializedAgents[this.agentIdentifier]?.api,delete r.initializedAgents[this.agentIdentifier]?.features,delete this.sharedAggregator;return r.ee.get(this.agentIdentifier).abort(),!1}}}({features:[R,k,j],loaderType:"lite"})})()})();</script>
|
||
<noscript><style>form.antibot * :not(.antibot-message) { display: none !important; }</style>
|
||
</noscript><script async src="https://www.googletagmanager.com/gtag/js?id=G-HEQ0YF2VYL"></script>
|
||
<script>window.dataLayer = window.dataLayer || [];function gtag(){dataLayer.push(arguments)};gtag("js", new Date());gtag("set", "developer_id.dMDhkMT", true);gtag('set', {'cookie_flags': 'SameSite=None;Secure', 'cookie_domain': 'www.nist.gov'});gtag("config", "G-HEQ0YF2VYL", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});gtag("config", "G-CSLL4ZEK4L", {"groups":"default","page_placeholder":"PLACEHOLDER_page_location","link_attribution":true,"allow_ad_personalization_signals":false});</script>
|
||
<link rel="canonical" href="https://www.nist.gov/blogs/taking-measure/categories/249121" />
|
||
<meta name="robots" content="follow, noindex" />
|
||
<link rel="shortlink" href="https://www.nist.gov/blogs/taking-measure/categories/249121" />
|
||
<meta name="citation_title" content="Blog Entries | NIST" />
|
||
<meta property="og:site_name" content="NIST" />
|
||
<meta property="og:type" content="Article" />
|
||
<meta property="og:url" content="https://www.nist.gov/blogs/taking-measure/categories/249121" />
|
||
<meta property="og:title" content="Blog Entries" />
|
||
<meta name="dcterms.title" content="Blog Entries" />
|
||
<meta name="dcterms.type" content="text" />
|
||
<meta name="dcterms.format" content="text/html" />
|
||
<meta name="dcterms.identifier" content="https://www.nist.gov/blogs/taking-measure/categories/249121" />
|
||
<meta name="dcterms.source" content="NIST" />
|
||
<meta name="twitter:card" content="summary_large_image" />
|
||
<meta name="twitter:site" content="NIST" />
|
||
<meta name="twitter:title" content="Blog Entries" />
|
||
<meta name="google-site-verification" content="QMu0ODkER3rN5hLcMLqNVf7e3bkjYsNLTuhqfH48jCA" />
|
||
<meta name="Generator" content="Drupal 10 (https://www.drupal.org)" />
|
||
<meta name="MobileOptimized" content="width" />
|
||
<meta name="HandheldFriendly" content="true" />
|
||
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
|
||
<link rel="icon" href="/themes/custom/nist_www/favicon.ico" type="image/vnd.microsoft.icon" />
|
||
|
||
<title>Taking Measure Blog: Time and frequency metrology</title>
|
||
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_ufIE7sXsYlDZf2Go6TUV8D-GajamfgHNP1NOD6rJ75g.css?delta=0&language=en&theme=nist_www&include=eJxFjY0KwzAIhF8o1EeS_MgWamKJplneflnXMRDxjvu84OOOJmsOCP8bc5TqalZDe1Kh5QkH37BIgpTVBybkXHenU43KYpWuPDxYgucvO8b4aXrZJw-p9cPzdkvHfko3XC-jnNQmSKUo7M5MQ-Ha2-rsTG94e0M8" />
|
||
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_kGS0ApDpFo-_3JI4Ijxg4RCWlTqsImK3lqH7bCv5v2U.css?delta=1&language=en&theme=nist_www&include=eJxFjY0KwzAIhF8o1EeS_MgWamKJplneflnXMRDxjvu84OOOJmsOCP8bc5TqalZDe1Kh5QkH37BIgpTVBybkXHenU43KYpWuPDxYgucvO8b4aXrZJw-p9cPzdkvHfko3XC-jnNQmSKUo7M5MQ-Ha2-rsTG94e0M8" />
|
||
<link rel="stylesheet" media="print" href="/sites/default/files/css/css_-IXwLuTUdm8IGHxib8GX8wWKw3LjKsNWSYYskZ5fEGg.css?delta=2&language=en&theme=nist_www&include=eJxFjY0KwzAIhF8o1EeS_MgWamKJplneflnXMRDxjvu84OOOJmsOCP8bc5TqalZDe1Kh5QkH37BIgpTVBybkXHenU43KYpWuPDxYgucvO8b4aXrZJw-p9cPzdkvHfko3XC-jnNQmSKUo7M5MQ-Ha2-rsTG94e0M8" />
|
||
<link rel="stylesheet" media="all" href="/sites/default/files/css/css_JblPwKLw45cPI6Z1CCNqTcKVNQKc2-R8DCddjdigut0.css?delta=3&language=en&theme=nist_www&include=eJxFjY0KwzAIhF8o1EeS_MgWamKJplneflnXMRDxjvu84OOOJmsOCP8bc5TqalZDe1Kh5QkH37BIgpTVBybkXHenU43KYpWuPDxYgucvO8b4aXrZJw-p9cPzdkvHfko3XC-jnNQmSKUo7M5MQ-Ha2-rsTG94e0M8" />
|
||
|
||
<script src="/sites/default/files/js/js_GM8kl6wk698qKTTwusj83bCoGHHtOZ1UinjY1sE_Qbk.js?scope=header&delta=0&language=en&theme=nist_www&include=eJxdjeEOgyAMhF9I10dqinTYCdQAyvb2A-eyxaQ_-l2vd4amBYu2WcH8dnzkwak6z0iR_KvIlOEqDFFywbs0zWqNXsliSS1EogNHn3OWwhLWpDvDVegth1ZmDtx61RtKGNSClUymBXuJy-EB59WQH88XmJkspy9irfXPwc_SH8GmbSV_O3HYhWvGxxZWDBw3OHjsPHZ-AyPAajY"></script>
|
||
|
||
</head>
|
||
<body>
|
||
<a href="#main-content" class="visually-hidden focusable" data-elastic-exclude>
|
||
Skip to main content
|
||
</a>
|
||
|
||
<div class="dialog-off-canvas-main-canvas" data-off-canvas-main-canvas>
|
||
|
||
<!-- nist-index-ignore-start -->
|
||
<section data-elastic-exclude class="usa-banner" aria-label="Official government website">
|
||
<div class="usa-accordion">
|
||
<header class="usa-banner__header">
|
||
<div class="usa-banner__inner">
|
||
<div class="grid-col-auto">
|
||
<img class="usa-banner__header-flag" src="/libraries/nist-component-library/dist/img/us_flag_small.png" alt="U.S. flag">
|
||
</div>
|
||
<div class="grid-col-fill tablet:grid-col-auto">
|
||
<p class="usa-banner__header-text">An official website of the United States government</p>
|
||
<p class="usa-banner__header-action" aria-hidden="true">Here’s how you know</p>
|
||
</div>
|
||
<button class="usa-accordion__button usa-banner__button" aria-expanded="false" aria-controls="gov-banner-default">
|
||
<span class="usa-banner__button-text">Here’s how you know</span>
|
||
</button>
|
||
</div>
|
||
</header>
|
||
<div class="usa-banner__content usa-accordion__content" id="gov-banner-default">
|
||
<div class="grid-row grid-gap-lg">
|
||
<div class="usa-banner__guidance tablet:grid-col-6">
|
||
<img class="usa-banner__icon usa-media-block__img" src="/libraries/nist-component-library/dist/img/icon-dot-gov.svg" role="img" alt="" aria-hidden="true">
|
||
<div class="usa-media-block__body">
|
||
<p>
|
||
<strong>Official websites use .gov</strong>
|
||
<br/>
|
||
A <strong>.gov</strong> website belongs to an official government organization in the United States.
|
||
</p>
|
||
</div>
|
||
</div>
|
||
<div class="usa-banner__guidance tablet:grid-col-6">
|
||
<img class="usa-banner__icon usa-media-block__img" src="/libraries/nist-component-library/dist/img/icon-https.svg" role="img" alt="" aria-hidden="true">
|
||
<div class="usa-media-block__body">
|
||
<p>
|
||
<strong>Secure .gov websites use HTTPS</strong>
|
||
<br/>
|
||
A <strong>lock</strong> ( <span class="icon-lock">
|
||
<svg xmlns="http://www.w3.org/2000/svg" width="52" height="64" viewbox="0 0 52 64" class="usa-banner__lock-image" role="img" aria-labelledby="banner-lock-title banner-lock-description" focusable="false">
|
||
<title id="banner-lock-title">Lock</title>
|
||
<desc id="banner-lock-description">A locked padlock</desc><path fill="#000000" fill-rule="evenodd" d="M26 0c10.493 0 19 8.507 19 19v9h3a4 4 0 0 1 4 4v28a4 4 0 0 1-4 4H4a4 4 0 0 1-4-4V32a4 4 0 0 1 4-4h3v-9C7 8.507 15.507 0 26 0zm0 8c-5.979 0-10.843 4.77-10.996 10.712L15 19v9h22v-9c0-6.075-4.925-11-11-11z"/></svg>
|
||
</span>
|
||
) or <strong>https://</strong> means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
|
||
</p>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</section>
|
||
<!-- nist-index-ignore-end -->
|
||
|
||
<div data-elastic-exclude>
|
||
<!-- nist-index-ignore-start -->
|
||
<div class="nist-print-header" style="display:none;">
|
||
<p class="nist-print-header__url">https://www.nist.gov/blogs/taking-measure/categories/249121</p>
|
||
<img class="nist-print-header__logo" width="289" height="38" src="/libraries/nist-component-library/dist/img/logo/nist_logo_sidestack.svg" alt="National Institute of Standards and Technology" />
|
||
</div>
|
||
|
||
|
||
<div class="usa-overlay"></div>
|
||
<header class="usa-header nist-header--www nist-header--minimal" role="banner">
|
||
<div class="usa-navbar">
|
||
<div class="usa-logo flex-fill">
|
||
<a href="/" title="National Institute of Standards and Technology" aria-label="Home">
|
||
<img src="/libraries/nist-component-library/dist/img/logo/logo.svg" alt="National Institute of Standards and Technology" width="300px" height="80px" />
|
||
</a>
|
||
</div>
|
||
<div class="usa-header__right grid-row flex-auto">
|
||
<div class="grid-col-fill nist-header__search-group">
|
||
|
||
<form class="usa-search usa-search--small"
|
||
accept-charset="UTF-8"
|
||
action="/search"
|
||
id="search_form"
|
||
method="get">
|
||
<div role="search">
|
||
<label class="usa-sr-only" for="search-form">Search NIST</label>
|
||
<input class="usa-input" id="search-form" type="search" name="s" placeholder="Search NIST" required="" maxlength="128">
|
||
<button class="usa-button" type="submit"><img src="/libraries/nist-component-library/dist/img/usa-icons-bg/search--white.svg" class="usa-search__submit-icon" alt="Search"></button>
|
||
</div>
|
||
</form>
|
||
</div>
|
||
<div class="grid-col-auto padding-left-1">
|
||
<button class="usa-menu-btn">Menu</button>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
|
||
|
||
|
||
|
||
<nav aria-label="Primary navigation" class="usa-nav">
|
||
<div class="usa-nav__inner">
|
||
<button class="usa-nav__close">Close</button>
|
||
<ul class="usa-nav__primary usa-accordion">
|
||
<li class="usa-nav__primary-item">
|
||
<a class="usa-nav__link" href="/publications">Publications</a>
|
||
</li>
|
||
<li class="usa-nav__primary-item">
|
||
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-2"><span>What We Do</span></button>
|
||
<div id="primary_menu-2" class="usa-nav__submenu usa-megamenu">
|
||
<div class="grid-row">
|
||
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/topics" class="usa-nav__link">All Topics</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/advanced-communications" class="usa-nav__link">Advanced communications</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/artificial-intelligence" class="usa-nav__link">Artificial intelligence</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/bioscience" class="usa-nav__link">Bioscience</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/buildings-construction" class="usa-nav__link">Buildings and construction</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/chemistry" class="usa-nav__link">Chemistry</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/cybersecurity" class="usa-nav__link">Cybersecurity</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/electronics" class="usa-nav__link">Electronics</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/energy" class="usa-nav__link">Energy</a>
|
||
</li>
|
||
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/environment" class="usa-nav__link">Environment</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/fire" class="usa-nav__link">Fire</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/forensic-science" class="usa-nav__link">Forensic science</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/health" class="usa-nav__link">Health</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/information-technology" class="usa-nav__link">Information technology</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/infrastructure" class="usa-nav__link">Infrastructure</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/manufacturing" class="usa-nav__link">Manufacturing</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/materials" class="usa-nav__link">Materials</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/mathematics-statistics" class="usa-nav__link">Mathematics and statistics</a>
|
||
</li>
|
||
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/metrology" class="usa-nav__link">Metrology</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/nanotechnology" class="usa-nav__link">Nanotechnology</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/neutron-research" class="usa-nav__link">Neutron research</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/performance-excellence" class="usa-nav__link">Performance excellence</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/physics" class="usa-nav__link">Physics</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/public-safety" class="usa-nav__link">Public safety</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/quantum-information-science" class="usa-nav__link">Quantum information science</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/resilience" class="usa-nav__link">Resilience</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/standards" class="usa-nav__link">Standards</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/transportation" class="usa-nav__link">Transportation</a>
|
||
</li>
|
||
</ul>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</li>
|
||
<li class="usa-nav__primary-item">
|
||
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-3"><span>Labs & Major Programs</span></button>
|
||
<div id="primary_menu-3" class="usa-nav__submenu usa-megamenu">
|
||
<div class="grid-row">
|
||
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/adlp" class="usa-nav__link">Assoc Director of Laboratory Programs</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/laboratories" class="usa-nav__link">Laboratories</a>
|
||
<ul class="usa-nav__submenu-list">
|
||
<li>
|
||
<a href="/ctl" class="usa-nav__link">Communications Technology Laboratory</a>
|
||
</li>
|
||
<li>
|
||
<a href="/el" class="usa-nav__link">Engineering Laboratory</a>
|
||
</li>
|
||
<li>
|
||
<a href="/itl" class="usa-nav__link">Information Technology Laboratory</a>
|
||
</li>
|
||
<li>
|
||
<a href="/mml" class="usa-nav__link">Material Measurement Laboratory</a>
|
||
</li>
|
||
<li>
|
||
<a href="/pml" class="usa-nav__link">Physical Measurement Laboratory</a>
|
||
</li>
|
||
</ul>
|
||
</li>
|
||
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/user-facilities" class="usa-nav__link">User Facilities</a>
|
||
<ul class="usa-nav__submenu-list">
|
||
<li>
|
||
<a href="/ncnr" class="usa-nav__link">NIST Center for Neutron Research</a>
|
||
</li>
|
||
<li>
|
||
<a href="/cnst" class="usa-nav__link">CNST NanoFab</a>
|
||
</li>
|
||
</ul>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/labs-major-programs/research-test-beds" class="usa-nav__link">Research Test Beds</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/laboratories/projects-programs" class="usa-nav__link">Research Projects</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/laboratories/tools-instruments" class="usa-nav__link">Tools & Instruments</a>
|
||
</li>
|
||
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/major-programs" class="usa-nav__link">Major Programs</a>
|
||
<ul class="usa-nav__submenu-list">
|
||
<li>
|
||
<a href="/baldrige" class="usa-nav__link">Baldrige Performance Excellence Program</a>
|
||
</li>
|
||
<li>
|
||
<a href="/chips" class="usa-nav__link">CHIPS for America Initiative</a>
|
||
</li>
|
||
<li>
|
||
<a href="/mep" class="usa-nav__link">Manufacturing Extension Partnership (MEP)</a>
|
||
</li>
|
||
<li>
|
||
<a href="/oam" class="usa-nav__link">Office of Advanced Manufacturing</a>
|
||
</li>
|
||
<li>
|
||
<a href="/spo" class="usa-nav__link">Special Programs Office</a>
|
||
</li>
|
||
<li>
|
||
<a href="/tpo" class="usa-nav__link">Technology Partnerships Office</a>
|
||
</li>
|
||
</ul>
|
||
</li>
|
||
</ul>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</li>
|
||
<li class="usa-nav__primary-item">
|
||
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-4"><span>Services & Resources</span></button>
|
||
<div id="primary_menu-4" class="usa-nav__submenu usa-megamenu">
|
||
<div class="grid-row">
|
||
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/content/standards-measurements" class="usa-nav__link">Standards and Measurements</a>
|
||
<ul class="usa-nav__submenu-list">
|
||
<li>
|
||
<a href="/calibrations" class="usa-nav__link">Calibration Services</a>
|
||
</li>
|
||
<li>
|
||
<a href="/nvlap" class="usa-nav__link">Laboratory Accreditation (NVLAP)</a>
|
||
</li>
|
||
<li>
|
||
<a href="/nist-quality-system" class="usa-nav__link">Quality System</a>
|
||
</li>
|
||
<li>
|
||
<a href="/srm" class="usa-nav__link">Standard Reference Materials (SRMs)</a>
|
||
</li>
|
||
<li>
|
||
<a href="/sri" class="usa-nav__link">Standard Reference Instruments (SRIs)</a>
|
||
</li>
|
||
<li>
|
||
<a href="/standardsgov" class="usa-nav__link">Standards.gov</a>
|
||
</li>
|
||
<li>
|
||
<a href="/pml/time-and-frequency-division/time-services" class="usa-nav__link">Time Services</a>
|
||
</li>
|
||
<li>
|
||
<a href="/pml/owm" class="usa-nav__link">Office of Weights and Measures</a>
|
||
</li>
|
||
</ul>
|
||
</li>
|
||
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/services-resources/software" class="usa-nav__link">Software</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/data" class="usa-nav__link">Data</a>
|
||
<ul class="usa-nav__submenu-list">
|
||
<li>
|
||
<a href="https://webbook.nist.gov/chemistry/" class="usa-nav__link">Chemistry WebBook</a>
|
||
</li>
|
||
<li>
|
||
<a href="https://nvd.nist.gov/" class="usa-nav__link">National Vulnerability Database</a>
|
||
</li>
|
||
<li>
|
||
<a href="/pml/productsservices/physical-reference-data" class="usa-nav__link">Physical Reference Data</a>
|
||
</li>
|
||
<li>
|
||
<a href="/srd" class="usa-nav__link">Standard Reference Data (SRD)</a>
|
||
</li>
|
||
</ul>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="https://shop.nist.gov/" class="usa-nav__link">Storefront</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/tpo" class="usa-nav__link">License & Patents</a>
|
||
</li>
|
||
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="https://csrc.nist.gov/" class="usa-nav__link">Computer Security Resource Center (CSRC)</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/nist-research-library" class="usa-nav__link">NIST Research Library</a>
|
||
</li>
|
||
</ul>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</li>
|
||
<li class="usa-nav__primary-item">
|
||
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-5"><span>News & Events</span></button>
|
||
<div id="primary_menu-5" class="usa-nav__submenu usa-megamenu">
|
||
<div class="grid-row">
|
||
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/news-events/news" class="usa-nav__link">News</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/news-events/events" class="usa-nav__link">Events</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/blogs" class="usa-nav__link">Blogs</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/feature-stories" class="usa-nav__link">Feature Stories</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/awards" class="usa-nav__link">Awards</a>
|
||
</li>
|
||
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/video-gallery" class="usa-nav__link">Video Gallery</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/image-gallery" class="usa-nav__link">Image Gallery</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/pao/media-contacts" class="usa-nav__link">Media Contacts</a>
|
||
</li>
|
||
</ul>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</li>
|
||
<li class="usa-nav__primary-item">
|
||
<button class="usa-accordion__button usa-nav__link" aria-expanded="false" aria-controls="primary_menu-6"><span>About NIST</span></button>
|
||
<div id="primary_menu-6" class="usa-nav__submenu usa-megamenu">
|
||
<div class="grid-row">
|
||
<div class="tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/about-nist" class="usa-nav__link">About Us</a>
|
||
<ul class="usa-nav__submenu-list">
|
||
<li>
|
||
<a href="/director/leadership" class="usa-nav__link">Leadership</a>
|
||
</li>
|
||
<li>
|
||
<a href="/director/nist-organization-structure" class="usa-nav__link">Organization Structure</a>
|
||
</li>
|
||
<li>
|
||
<a href="/about-nist/budget-planning" class="usa-nav__link">Budget & Planning</a>
|
||
</li>
|
||
</ul>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/about-nist/contact-us" class="usa-nav__link">Contact Us</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/about-nist/visit" class="usa-nav__link">Visit</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/careers" class="usa-nav__link">Careers</a>
|
||
<ul class="usa-nav__submenu-list">
|
||
<li>
|
||
<a href="/iaao/academic-affairs-office" class="usa-nav__link">Student programs</a>
|
||
</li>
|
||
</ul>
|
||
</li>
|
||
</ul></div><div class="column-break tablet:grid-col-fill"><ul class="usa-nav__submenu-list">
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/about-nist/work-nist" class="usa-nav__link">Work with NIST</a>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/history" class="usa-nav__link">History</a>
|
||
<ul class="usa-nav__submenu-list">
|
||
<li>
|
||
<a href="http://nistdigitalarchives.contentdm.oclc.org/" class="usa-nav__link">NIST Digital Archives</a>
|
||
</li>
|
||
<li>
|
||
<a href="/nist-museum" class="usa-nav__link">NIST Museum</a>
|
||
</li>
|
||
<li>
|
||
<a href="/nist-and-nobel" class="usa-nav__link">NIST and the Nobel</a>
|
||
</li>
|
||
</ul>
|
||
</li>
|
||
<li class="usa-nav__submenu-item">
|
||
<a href="/education" class="usa-nav__link">Educational Resources</a>
|
||
</li>
|
||
</ul>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</li>
|
||
</ul>
|
||
</div>
|
||
</nav>
|
||
|
||
|
||
|
||
|
||
</header>
|
||
<!-- nist-index-ignore-end -->
|
||
</div>
|
||
|
||
<div class="grid-container">
|
||
|
||
|
||
|
||
|
||
</div>
|
||
|
||
|
||
|
||
|
||
|
||
<div class="nist-blog-header nist-blog-header--purple nist-blog-header--inner">
|
||
<div class="nist-blog-header__bkgrd">
|
||
<div class="nist-blog-header__main grid-container">
|
||
<div class="grid-row">
|
||
<h2 class="nist-blog-header__title">
|
||
<a href="/blogs/taking-measure"> Taking Measure
|
||
</a>
|
||
</h2>
|
||
<div class="nist-blog-header__tagline">
|
||
<p class="text">Just a Standard Blog</p>
|
||
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
|
||
<div class="grid-container">
|
||
<div class="grid-row grid-gap-6 padding-top-4">
|
||
<div class="tablet:grid-col-8">
|
||
|
||
|
||
<h1 class="nist-page__title">Time and frequency metrology </h1>
|
||
|
||
|
||
|
||
|
||
|
||
|
||
<div
|
||
id="block-nist-www-content" class="nist-block"
|
||
>
|
||
|
||
|
||
<div class="views-element-container"><div class="js-view-dom-id-5fa758599f1d2109753430e7f85e475293da86bcdfe4b2329107b578adbb61f0">
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
<div>
|
||
|
||
<article
|
||
about="/blogs/taking-measure/keepers-right-answer-why-measurements-nist-are-important-nation-and-world" class="nist-teaser"
|
||
>
|
||
<div class="nist-teaser__image">
|
||
<div class="entity-reference"> <a href="/blogs/taking-measure/keepers-right-answer-why-measurements-nist-are-important-nation-and-world" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2024/09/10/Jim-olthoff.png?itok=s21CFmxA" width="82" height="100" alt="NIST Chief Metrologist Jim Olthoff stands in front of equipment in a lab. " typeof="foaf:Image" />
|
||
|
||
</a>
|
||
</div>
|
||
|
||
</div>
|
||
<div class="nist-teaser__content-wrapper">
|
||
<header>
|
||
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/keepers-right-answer-why-measurements-nist-are-important-nation-and-world"><span>Keepers of the Right Answer: Why Measurements at NIST Are Important for the Nation and the World</span>
|
||
</a></h3>
|
||
<div class="nist-teaser__date">
|
||
<div class="daterange"><time datetime="2024-09-11T12:00:00Z">September 11, 2024</time>
|
||
</div>
|
||
|
||
</div>
|
||
|
||
</header>
|
||
<div class="nist-teaser__content">
|
||
<div class="text-with-summary"> Practically everything you use in your everyday life works because of measurement science.
|
||
|
||
</div>
|
||
|
||
</div>
|
||
</div>
|
||
</article>
|
||
</div>
|
||
<div>
|
||
|
||
<article
|
||
about="/blogs/taking-measure/scientific-christmas-tale" class="nist-teaser"
|
||
>
|
||
<div class="nist-teaser__image">
|
||
<div class="entity-reference"> <a href="/blogs/taking-measure/scientific-christmas-tale" hreflang="en"><img loading="lazy" src="/sites/default/files/images/2023/12/04/NightbeforeXmas_Title_v2_Test-A.gif" width="960" height="600" alt="Title card reads "A Scientific Christmas Tale" with the NIST logo in a wreath and flashing holiday lights. " typeof="foaf:Image" />
|
||
</a>
|
||
</div>
|
||
|
||
</div>
|
||
<div class="nist-teaser__content-wrapper">
|
||
<header>
|
||
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/scientific-christmas-tale"><span>A Scientific Christmas Tale</span>
|
||
</a></h3>
|
||
<div class="nist-teaser__date">
|
||
<div class="daterange"><time datetime="2023-12-19T12:00:00Z">December 19, 2023</time>
|
||
</div>
|
||
|
||
</div>
|
||
|
||
</header>
|
||
<div class="nist-teaser__content">
|
||
<div class="text-with-summary"> ’Twas the night before Christmas; NIST staff had gone home. Our director was left to reflect all alone. She thought about NIST and the breadth of its work, from
|
||
|
||
</div>
|
||
|
||
</div>
|
||
</div>
|
||
</article>
|
||
</div>
|
||
<div>
|
||
|
||
<article
|
||
about="/blogs/taking-measure/auld-lang-time-one-countrys-timekeepers-makes-sure-we-ring-new-year-just-right" class="nist-teaser"
|
||
>
|
||
<div class="nist-teaser__image">
|
||
<div class="entity-reference"> <a href="/blogs/taking-measure/auld-lang-time-one-countrys-timekeepers-makes-sure-we-ring-new-year-just-right" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2023/11/27/shutterstock_89929708.jpg?itok=RGvtZ-ht" width="100" height="67" alt="An antique clock showing a few minutes before 12 is topped with a party hat, and colorful streamers hang in the background. " typeof="foaf:Image" />
|
||
|
||
</a>
|
||
</div>
|
||
|
||
</div>
|
||
<div class="nist-teaser__content-wrapper">
|
||
<header>
|
||
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/auld-lang-time-one-countrys-timekeepers-makes-sure-we-ring-new-year-just-right"><span>Auld Lang ‘Time’: One of the Country’s Timekeepers Makes Sure We Ring in The New Year at Just the Right Second</span>
|
||
</a></h3>
|
||
<div class="nist-teaser__date">
|
||
<div class="daterange"><time datetime="2023-12-28T12:00:00Z">December 28, 2023</time>
|
||
</div>
|
||
|
||
</div>
|
||
|
||
</header>
|
||
<div class="nist-teaser__content">
|
||
<div class="text-with-summary"> As you prepare to watch the ball drop or pop champagne on New Year’s Eve, we’ll be keeping an eye on the clock — just as we always do.
|
||
|
||
</div>
|
||
|
||
</div>
|
||
</div>
|
||
</article>
|
||
</div>
|
||
<div>
|
||
|
||
<article
|
||
about="/blogs/taking-measure/think-you-know-what-second-it-will-likely-change-next-decade" class="nist-teaser"
|
||
>
|
||
<div class="nist-teaser__image">
|
||
<div class="entity-reference"> <a href="/blogs/taking-measure/think-you-know-what-second-it-will-likely-change-next-decade" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2023/10/16/tara_fortier_working_in_lab_october_2023.jpg?itok=RkM9HePP" width="100" height="67" alt="A researcher wearing safety glasses reaches into a box of circuitry and other equipment, which emits a green glow. " typeof="foaf:Image" />
|
||
|
||
</a>
|
||
</div>
|
||
|
||
</div>
|
||
<div class="nist-teaser__content-wrapper">
|
||
<header>
|
||
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/think-you-know-what-second-it-will-likely-change-next-decade"><span>Think You Know What a Second Is? It Will Likely Change in the Next Decade.</span>
|
||
</a></h3>
|
||
<div class="nist-teaser__date">
|
||
<div class="daterange"><time datetime="2023-11-08T12:00:00Z">November 8, 2023</time>
|
||
</div>
|
||
|
||
</div>
|
||
|
||
</header>
|
||
<div class="nist-teaser__content">
|
||
<div class="text-with-summary"> As the world has modernized and our pace of life has increased, our relationship to time has changed.
|
||
|
||
</div>
|
||
|
||
</div>
|
||
</div>
|
||
</article>
|
||
</div>
|
||
<div>
|
||
|
||
<article
|
||
about="/blogs/taking-measure/everyday-time-and-atomic-time-part-5" class="nist-teaser"
|
||
>
|
||
<div class="nist-teaser__image">
|
||
<div class="entity-reference"> <a href="/blogs/taking-measure/everyday-time-and-atomic-time-part-5" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2021/04/28/leap%20seconds_2x_v2-01.png?itok=bwIJKES_" width="100" height="63" alt="digital clock in orbit around Earth. The clock face reads 11:59:60. " typeof="foaf:Image" />
|
||
|
||
</a>
|
||
</div>
|
||
|
||
</div>
|
||
<div class="nist-teaser__content-wrapper">
|
||
<header>
|
||
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/everyday-time-and-atomic-time-part-5"><span>Everyday Time and Atomic Time: Part 5</span>
|
||
</a></h3>
|
||
<div class="nist-teaser__date">
|
||
<div class="daterange"><time datetime="2021-04-28T12:00:00Z">April 28, 2021</time>
|
||
</div>
|
||
|
||
</div>
|
||
|
||
</header>
|
||
<div class="nist-teaser__content">
|
||
<div class="text-with-summary"> This is part 5 in a series. Read part 1, part 2, part 3 and part 4. The Leap Second Solution When atomic clocks were developed in the 1950s, scientists needed
|
||
|
||
</div>
|
||
|
||
</div>
|
||
</div>
|
||
</article>
|
||
</div>
|
||
<div>
|
||
|
||
<article
|
||
about="/blogs/taking-measure/everyday-time-and-atomic-time-part-4" class="nist-teaser"
|
||
>
|
||
<div class="nist-teaser__image">
|
||
<div class="entity-reference"> <a href="/blogs/taking-measure/everyday-time-and-atomic-time-part-4" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2021/04/20/shutterstock_312319736_GMaple%20Design.jpg?itok=Dd7XrbNU" width="100" height="63" alt="pair of feet standing on either side of the prime meridian in Greenwich, England" typeof="foaf:Image" />
|
||
|
||
</a>
|
||
</div>
|
||
|
||
</div>
|
||
<div class="nist-teaser__content-wrapper">
|
||
<header>
|
||
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/everyday-time-and-atomic-time-part-4"><span>Everyday Time and Atomic Time: Part 4</span>
|
||
</a></h3>
|
||
<div class="nist-teaser__date">
|
||
<div class="daterange"><time datetime="2021-04-21T12:00:00Z">April 21, 2021</time>
|
||
</div>
|
||
|
||
</div>
|
||
|
||
</header>
|
||
<div class="nist-teaser__content">
|
||
<div class="text-with-summary"> This is part 4 in a series. Read part 1 , part 2 and part 3 . Greenwich Mean Time In the previous essay I introduced mean solar time, which averaged the annual
|
||
|
||
</div>
|
||
|
||
</div>
|
||
</div>
|
||
</article>
|
||
</div>
|
||
<div>
|
||
|
||
<article
|
||
about="/blogs/taking-measure/everyday-time-and-atomic-time-part-3" class="nist-teaser"
|
||
>
|
||
<div class="nist-teaser__image">
|
||
<div class="entity-reference"> <a href="/blogs/taking-measure/everyday-time-and-atomic-time-part-3" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2021/04/09/grandfatherclock_julioricco_SS_1476320567.jpg?itok=wbso-KFi" width="100" height="63" alt="wood pendulum clock hung on a wood paneled wall" typeof="foaf:Image" />
|
||
|
||
</a>
|
||
</div>
|
||
|
||
</div>
|
||
<div class="nist-teaser__content-wrapper">
|
||
<header>
|
||
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/everyday-time-and-atomic-time-part-3"><span>Everyday Time and Atomic Time: Part 3</span>
|
||
</a></h3>
|
||
<div class="nist-teaser__date">
|
||
<div class="daterange"><time datetime="2021-04-14T12:00:00Z">April 14, 2021</time>
|
||
</div>
|
||
|
||
</div>
|
||
|
||
</header>
|
||
<div class="nist-teaser__content">
|
||
<div class="text-with-summary"> This is part 3 in a series. Read part 1 and part 2 . Oscillators and Clocks In the previous essay, I introduced the ideas that frequency and time interval are
|
||
|
||
</div>
|
||
|
||
</div>
|
||
</div>
|
||
</article>
|
||
</div>
|
||
<div>
|
||
|
||
<article
|
||
about="/blogs/taking-measure/everyday-time-and-atomic-time-part-2" class="nist-teaser"
|
||
>
|
||
<div class="nist-teaser__image">
|
||
<div class="entity-reference"> <a href="/blogs/taking-measure/everyday-time-and-atomic-time-part-2" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2021/04/06/shutterstock_48509689_960x600.jpg?itok=ZSB38Lvc" width="100" height="63" alt="pipe organ" typeof="foaf:Image" />
|
||
|
||
</a>
|
||
</div>
|
||
|
||
</div>
|
||
<div class="nist-teaser__content-wrapper">
|
||
<header>
|
||
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/everyday-time-and-atomic-time-part-2"><span>Everyday Time and Atomic Time: Part 2</span>
|
||
</a></h3>
|
||
<div class="nist-teaser__date">
|
||
<div class="daterange"><time datetime="2021-04-07T12:00:00Z">April 7, 2021</time>
|
||
</div>
|
||
|
||
</div>
|
||
|
||
</header>
|
||
<div class="nist-teaser__content">
|
||
<div class="text-with-summary"> This is part 2 in a series. Read part 1. A short history of frequency Frequency was originally considered to be the province of musicians. The pitches or
|
||
|
||
</div>
|
||
|
||
</div>
|
||
</div>
|
||
</article>
|
||
</div>
|
||
<div>
|
||
|
||
<article
|
||
about="/blogs/taking-measure/everyday-time-and-atomic-time-part-1" class="nist-teaser"
|
||
>
|
||
<div class="nist-teaser__image">
|
||
<div class="entity-reference"> <a href="/blogs/taking-measure/everyday-time-and-atomic-time-part-1" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2021/03/16/Judah%20Levine%20with%20time%20scale.jpg?itok=ilaSyhzG" width="100" height="63" alt="NIST physicist Judah Levine with the NIST time scale, a digital clock face reading 14:33:34 and a bank of atomic clocks. " typeof="foaf:Image" />
|
||
|
||
</a>
|
||
</div>
|
||
|
||
</div>
|
||
<div class="nist-teaser__content-wrapper">
|
||
<header>
|
||
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/everyday-time-and-atomic-time-part-1"><span>Everyday Time and Atomic Time: Part 1</span>
|
||
</a></h3>
|
||
<div class="nist-teaser__date">
|
||
<div class="daterange"><time datetime="2021-03-31T12:00:00Z">March 31, 2021</time>
|
||
</div>
|
||
|
||
</div>
|
||
|
||
</header>
|
||
<div class="nist-teaser__content">
|
||
<div class="text-with-summary"> As a physicist in the National Institute of Standards and Technology (NIST) Time and Frequency Division, I have worked in the general area of operating atomic
|
||
|
||
</div>
|
||
|
||
</div>
|
||
</div>
|
||
</article>
|
||
</div>
|
||
<div>
|
||
|
||
<article
|
||
about="/blogs/taking-measure/nists-role-tv-throughout-decades" class="nist-teaser"
|
||
>
|
||
<div class="nist-teaser__image">
|
||
<div class="entity-reference"> <a href="/blogs/taking-measure/nists-role-tv-throughout-decades" hreflang="en"><img loading="lazy" src="/sites/default/files/styles/thumbnail/public/images/2020/07/23/Rainbow%20Revue%20Dellinger.jpg?itok=RHY9IGv1" width="100" height="63" alt="man on a television set in front of a painting of a lighthouse and a ship at sea" typeof="foaf:Image" />
|
||
|
||
</a>
|
||
</div>
|
||
|
||
</div>
|
||
<div class="nist-teaser__content-wrapper">
|
||
<header>
|
||
<h3 class="nist-teaser__title"><a href="/blogs/taking-measure/nists-role-tv-throughout-decades"><span>NIST’s Role in TV Throughout the Decades</span>
|
||
</a></h3>
|
||
<div class="nist-teaser__date">
|
||
<div class="daterange"><time datetime="2020-07-28T12:00:00Z">July 28, 2020</time>
|
||
</div>
|
||
|
||
</div>
|
||
|
||
</header>
|
||
<div class="nist-teaser__content">
|
||
<div class="text-with-summary"> The Academy of Television Arts & Sciences today announced nominations for the 2020 Primetime Emmy Awards, which recognize some of the best TV shows of the year
|
||
|
||
</div>
|
||
|
||
</div>
|
||
</div>
|
||
</article>
|
||
</div>
|
||
|
||
<nav class="pager" role="navigation" aria-labelledby="pagination-heading">
|
||
<h4 class="visually-hidden">Pagination</h4>
|
||
<ul class="pager__items js-pager__items">
|
||
<li>
|
||
Page 1 </li>
|
||
<li>
|
||
<a href="/blogs/taking-measure/categories/249121?page=1" title="Go to next page" rel="next">
|
||
<span class="visually-hidden">Next page</span>
|
||
<span aria-hidden="true">››</span>
|
||
</a>
|
||
</li>
|
||
</ul>
|
||
</nav>
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
</div>
|
||
</div>
|
||
|
||
|
||
</div>
|
||
|
||
|
||
</div>
|
||
<div class="tablet:grid-col-4">
|
||
<div about="/blogs/taking-measure">
|
||
|
||
|
||
<div
|
||
class="nist-block no-print"
|
||
>
|
||
|
||
<h2
|
||
class="nist-block__title"
|
||
>Our Science in Your Inbox</h2>
|
||
|
||
<div class="text-long"><p>Subscribe to our weekly emails.</p>
|
||
<form action="https://public.govdelivery.com/accounts/USNIST/subscribers/qualify" accept-charset="UTF-8" method="post">
|
||
<input name="utf8" type="hidden" value="✓">
|
||
<input type="hidden" name="authenticity_token" value="GleKn0r3EFkuIRsIWsyLN6Mrqim4qc3U7eIUCWGqBFz2ziQ/qv0gnQTJUhVbKHMSlmrsC7UHIm6S8IfK6qk9EQ==">
|
||
<input type="hidden" name="topic_id" id="topic_id" value="USNIST_309">
|
||
<div class="grid-row grid-gap-1">
|
||
<div class="tablet:grid-col-8">
|
||
<label class="usa-sr-only" for="email">Enter Email Address</label>
|
||
<input class="usa-input" type="text" name="email" id="email" title="email" placeholder="Your Email Address">
|
||
</div>
|
||
<div class="tablet:grid-col-4">
|
||
<input type="submit" name="commit" value="Sign Up" class="usa-button margin-top-1">
|
||
</div>
|
||
</div>
|
||
</form>
|
||
</div>
|
||
|
||
|
||
</div>
|
||
|
||
<div
|
||
class="views-exposed-form usa-form filters nist-block" novalidate="novalidate" data-drupal-selector="views-exposed-form-search-blog-taking-measure-search-page"
|
||
>
|
||
|
||
<h2
|
||
class="nist-block__title"
|
||
>Search</h2>
|
||
|
||
<form action="/blogs/taking-measure/search/taking-measure" method="get" id="views-exposed-form-search-blog-taking-measure-search-page" accept-charset="UTF-8" class="usa-form">
|
||
<div class="form-item js-form-item form-type-textfield js-form-type-textfield form-item-k js-form-item-k form-no-label">
|
||
|
||
|
||
<input placeholder="Search this blog" data-drupal-selector="edit-k" type="text" id="edit-k" name="k" value="" size="30" maxlength="128" class="form-text usa-input" />
|
||
|
||
|
||
|
||
<div id="edit-k--description" class="description help-block">
|
||
Put exact phrase in quotes (e.g., "artificial intelligence")
|
||
</div>
|
||
</div>
|
||
<div class="grid-col-12 form-actions js-form-wrapper form-wrapper" data-drupal-selector="edit-actions" id="edit-actions"><input data-drupal-selector="edit-submit-search-blog" type="submit" id="edit-submit-search-blog" value="Search" class="button js-form-submit form-submit usa-button" /></div>
|
||
|
||
|
||
</form>
|
||
|
||
|
||
</div>
|
||
<div
|
||
class="nist-block no-print"
|
||
>
|
||
|
||
<h2
|
||
class="nist-block__title"
|
||
>Stay connected</h2>
|
||
|
||
|
||
|
||
<div><a href="https://www.facebook.com/nist" class="nist-social nist-social--facebook" title="Facebook" ><span>Facebook</span></a><a href="https://www.linkedin.com/company/nist" class="nist-social nist-social--linkedin" title="LinkedIn" ><span>LinkedIn</span></a><a href="https://www.x.com/nist" class="nist-social nist-social--x" title="X (Twitter)" ><span>X (Twitter)</span></a><a href="https://www.youtube.com/nist" class="nist-social nist-social--youtube" title="Youtube" ><span>Youtube</span></a><a href="https://www.instagram.com/nist/" class="nist-social nist-social--instagram" title="Instagram" ><span>Instagram</span></a><a href="https://public.govdelivery.com/accounts/USNIST/subscriber/new?topic_id=USNIST_309" class="nist-social nist-social--envelope" title="GovDelivery" ><span>GovDelivery</span></a></div>
|
||
|
||
</div>
|
||
|
||
<div
|
||
class="views-element-container nist-block"
|
||
>
|
||
|
||
<h2
|
||
class="nist-block__title"
|
||
>Categories</h2>
|
||
|
||
<div><div class="js-view-dom-id-e0e4658ebfeccd496441506bb1e74e0accc62d6dc996fc3fa08ca98f972c326d">
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
<div>
|
||
<select class="usa-select ViewsJumpMenu js-viewsJumpMenu" title="-- Choose --" id="blog-categories-takingm-jump-menu">
|
||
<option>-- Choose --</option>
|
||
<option data-url="/blogs/taking-measure/categories/249466">Advanced communications</option>
|
||
<option data-url="/blogs/taking-measure/categories/248321">Bioscience</option>
|
||
<option data-url="/blogs/taking-measure/categories/248371">Buildings and Construction</option>
|
||
<option data-url="/blogs/taking-measure/categories/248416">Chemistry</option>
|
||
<option data-url="/blogs/taking-measure/categories/248486">Electronics</option>
|
||
<option data-url="/blogs/taking-measure/categories/248531">Energy</option>
|
||
<option data-url="/blogs/taking-measure/categories/248561">Environment</option>
|
||
<option data-url="/blogs/taking-measure/categories/248586">Fire</option>
|
||
<option data-url="/blogs/taking-measure/categories/248616">Forensic Science</option>
|
||
<option data-url="/blogs/taking-measure/categories/248651">Health</option>
|
||
<option data-url="/blogs/taking-measure/categories/249421">Information technology</option>
|
||
<option data-url="/blogs/taking-measure/categories/2748236">Infrastructure</option>
|
||
<option data-url="/blogs/taking-measure/categories/248866">Manufacturing</option>
|
||
<option data-url="/blogs/taking-measure/categories/248946">Materials</option>
|
||
<option data-url="/blogs/taking-measure/categories/249011">Mathematics and statistics</option>
|
||
<option data-url="/blogs/taking-measure/categories/249051">Metrology</option>
|
||
<option data-url="/blogs/taking-measure/categories/249126">Nanotechnology</option>
|
||
<option data-url="/blogs/taking-measure/categories/249451">Neutron research</option>
|
||
<option data-url="/blogs/taking-measure/categories/249426">Performance excellence</option>
|
||
<option data-url="/blogs/taking-measure/categories/249241">Physics</option>
|
||
<option data-url="/blogs/taking-measure/categories/249461">Public safety</option>
|
||
<option data-url="/blogs/taking-measure/categories/249456">Resilience</option>
|
||
<option data-url="/blogs/taking-measure/categories/249341">Standards</option>
|
||
<option data-url="/blogs/taking-measure/categories/2813456">Technology transfer</option>
|
||
<option data-url="/blogs/taking-measure/categories/249396">Transportation</option>
|
||
</select>
|
||
</div>
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
|
||
</div>
|
||
</div>
|
||
|
||
|
||
</div>
|
||
|
||
|
||
</div>
|
||
|
||
</div>
|
||
</div>
|
||
</div>
|
||
|
||
<div data-elastic-exclude>
|
||
<!-- nist-index-ignore-start -->
|
||
|
||
<footer class="nist-footer padding-bottom-4">
|
||
|
||
|
||
<div class="grid-container nist-footer__info">
|
||
<div class="grid-row">
|
||
<div class="tablet:grid-col-6">
|
||
<div class="nist-footer__logo">
|
||
<a href="/" title="National Institute of Standards and Technology" rel="home">
|
||
<img class="nist-footer__logo-img" src="/libraries/nist-component-library/dist/img/logo/NIST-Logo-Brand-White.svg" alt="National Institute of Standards and Technology logo" width="300px" height="42px" />
|
||
</a>
|
||
</div>
|
||
<div class="nist-footer__contact">
|
||
<h3 class="nist-footer__contact-heading">HEADQUARTERS</h3>
|
||
<address>
|
||
100 Bureau Drive<br>
|
||
Gaithersburg, MD 20899<br>
|
||
<a href="tel:301-975-2000">301-975-2000</a>
|
||
</address>
|
||
<p>
|
||
<a href="mailto:do-webmaster@nist.gov">Webmaster</a> | <a href="https://www.nist.gov/about-nist/contact-us">Contact Us</a> | <a href="https://www.nist.gov/visit">Our Other Offices</a>
|
||
</p>
|
||
</div>
|
||
</div>
|
||
<div class="tablet:grid-col-6">
|
||
<div class="nist-footer__social-links">
|
||
|
||
<a class="nist-social nist-social--x-white" href=" https://x.com/NIST">
|
||
<span>X.com</span>
|
||
</a>
|
||
|
||
<a class="nist-social nist-social--facebook-white" href=" https://www.facebook.com/NIST">
|
||
<span>Facebook</span>
|
||
</a>
|
||
|
||
<a class="nist-social nist-social--linkedin-white" href=" https://www.linkedin.com/company/nist">
|
||
<span>LinkedIn</span>
|
||
</a>
|
||
|
||
<a class="nist-social nist-social--instagram-white" href=" https://www.instagram.com/nist/">
|
||
<span>Instagram</span>
|
||
</a>
|
||
|
||
<a class="nist-social nist-social--youtube-white" href=" https://www.youtube.com/NIST">
|
||
<span>YouTube</span>
|
||
</a>
|
||
|
||
<a class="nist-social nist-social--giphy-white" href=" https://giphy.com/nist">
|
||
<span>Giphy</span>
|
||
</a>
|
||
|
||
<a class="nist-social nist-social--rss-white" href=" https://www.nist.gov/news-events/nist-rss-feeds">
|
||
<span>RSS Feed</span>
|
||
</a>
|
||
|
||
<a class="nist-social nist-social--envelope-white" href=" https://public.govdelivery.com/accounts/USNIST/subscriber/new">
|
||
<span>Mailing List</span>
|
||
</a>
|
||
</div>
|
||
<div class="nist-footer__feedback">
|
||
How are we doing? <a class="usa-button" rel="nofollow" href="/form/nist-gov-feedback?destination=/blogs/taking-measure/categories/249121" title="Provide feedback">Feedback</a>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
</div>
|
||
|
||
|
||
<div class="grid-container">
|
||
<div class="nist-footer__nav" role="navigation">
|
||
<ul>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="https://www.nist.gov/privacy-policy">Site Privacy</a>
|
||
</li>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="https://www.nist.gov/oism/accessibility">Accessibility</a>
|
||
</li>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="https://www.nist.gov/privacy">Privacy Program</a>
|
||
</li>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="https://www.nist.gov/oism/copyrights">Copyrights</a>
|
||
</li>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="https://www.commerce.gov/vulnerability-disclosure-policy">Vulnerability Disclosure</a>
|
||
</li>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="https://www.nist.gov/no-fear-act-policy">No Fear Act Policy</a>
|
||
</li>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="https://www.nist.gov/office-director/freedom-information-act">FOIA</a>
|
||
</li>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="https://www.nist.gov/environmental-policy-statement">Environmental Policy</a>
|
||
</li>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="https://www.nist.gov/summary-report-scientific-integrity">Scientific Integrity</a>
|
||
</li>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="https://www.nist.gov/nist-information-quality-standards">Information Quality Standards</a>
|
||
</li>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="https://www.commerce.gov/">Commerce.gov</a>
|
||
</li>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="http://www.science.gov/">Science.gov</a>
|
||
</li>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="http://www.usa.gov/">USA.gov</a>
|
||
</li>
|
||
<li class="nist-footer__menu-item">
|
||
<a href="https://vote.gov/">Vote.gov</a>
|
||
</li>
|
||
</ul>
|
||
</div>
|
||
</div>
|
||
|
||
|
||
</footer>
|
||
<!-- nist-index-ignore-end -->
|
||
</div>
|
||
|
||
</div>
|
||
|
||
|
||
|
||
<script type="application/json" data-drupal-selector="drupal-settings-json">{"path":{"baseUrl":"\/","pathPrefix":"","currentPath":"blogs\/taking-measure\/categories\/249121","currentPathIsAdmin":false,"isFront":false,"currentLanguage":"en"},"pluralDelimiter":"\u0003","suppressDeprecationErrors":true,"back_to_top":{"back_to_top_button_trigger":100,"back_to_top_speed":1200,"back_to_top_prevent_on_mobile":false,"back_to_top_prevent_in_admin":true,"back_to_top_button_type":"image","back_to_top_button_text":"Back to top"},"google_analytics":{"account":"G-HEQ0YF2VYL","trackOutbound":true,"trackMailto":true,"trackTel":true,"trackDownload":true,"trackDownloadExtensions":"7z|aac|arc|arj|asf|asx|avi|bin|bsh|c|csv|doc(x|m)?|dot(x|m)?|dw(fx|g|gd)|dxf|eps|epub|exe|f(90)|flv|gif|gz|gzip|hqx|jar|jpe?g|js|m1v|mp(2|3|4|e?g)|mobi|mov(ie)?|msi|msp|pdf|phps|pl|png|ppt(x|m)?|pot(x|m)?|pps(x|m)?|ppam|sld(x|m)?|thmx|qtm?|ra(m|r)?|rfa|rtf|rvt|sch|sea|sit|swf|tar|tgz|tif|txt|txz|wav|wma|wmv|wpd|wrl|xls(x|m|b)?|xlt(x|m)|xlam|xml|xsd|z|zip"},"nist_search":{"clickTracking":"search-report-click","isDebug":false,"clickTrackEnabled":true,"message":"NIST Search in debug mode. Check the browsers network inspector for Click Track reporting results..."},"data":{"extlink":{"extTarget":false,"extTargetNoOverride":false,"extNofollow":false,"extNoreferrer":false,"extFollowNoOverride":false,"extClass":"ext","extLabel":"(link is external)","extImgClass":false,"extSubdomains":true,"extExclude":"\\.gov\\\/|\\.mil\\\/|\\manufacturingusa\\.com\\\/","extInclude":"","extCssExclude":".ck-editor, .nist-video-thumbnail__lightbox-trigger, a.nist-icon--mail-blue","extCssExplicit":"","extAlert":true,"extAlertText":"Thank you for visiting NIST. We hope your visit was informative. We have provided a link to this site because it has information that may be of interest to our users. NIST does not necessarily endorse the views expressed or the facts presented on this site. Further, NIST does not endorse any commercial products that may be advertised or available on this site. Click OK to be directed to your link.","mailtoClass":"0","mailtoLabel":"(link sends email)","extUseFontAwesome":false,"extIconPlacement":"after","extFaLinkClasses":"fa fa-external-link","extFaMailtoClasses":"fa fa-envelope-o","whitelistedDomains":[]}},"viewsJumpMenu":{"blog-categories-takingm-jump-menu":{"new_window":false}},"ajaxTrustedUrl":{"\/blogs\/taking-measure\/search\/taking-measure":true},"user":{"uid":0,"permissionsHash":"bd6a443844dbe99b4e6942f3b1397526e760137efd2b1ee6b2d588fc414dff20"}}</script>
|
||
<script src="/sites/default/files/js/js_jDaFaXhHm6gPUKstNYX9eIyoQXghVs3g7rbR0QoqpYY.js?scope=footer&delta=0&language=en&theme=nist_www&include=eJxdjeEOgyAMhF9I10dqinTYCdQAyvb2A-eyxaQ_-l2vd4amBYu2WcH8dnzkwak6z0iR_KvIlOEqDFFywbs0zWqNXsliSS1EogNHn3OWwhLWpDvDVegth1ZmDtx61RtKGNSClUymBXuJy-EB59WQH88XmJkspy9irfXPwc_SH8GmbSV_O3HYhWvGxxZWDBw3OHjsPHZ-AyPAajY"></script>
|
||
<script src="https://siteimproveanalytics.com/js/siteanalyze_6017546.js" async></script>
|
||
<script src="/sites/default/files/js/js_Dmlsg796Gcg1iFe2_jDlDs_CLplFV4oHrpZGx1_GQU0.js?scope=footer&delta=2&language=en&theme=nist_www&include=eJxdjeEOgyAMhF9I10dqinTYCdQAyvb2A-eyxaQ_-l2vd4amBYu2WcH8dnzkwak6z0iR_KvIlOEqDFFywbs0zWqNXsliSS1EogNHn3OWwhLWpDvDVegth1ZmDtx61RtKGNSClUymBXuJy-EB59WQH88XmJkspy9irfXPwc_SH8GmbSV_O3HYhWvGxxZWDBw3OHjsPHZ-AyPAajY"></script>
|
||
<script type="text/javascript">window.NREUM||(NREUM={});NREUM.info={"beacon":"bam.nr-data.net","licenseKey":"37b7ccb661","applicationID":"1089704227","transactionName":"YFxUN0sADEdYVkBaClkWdwBNCA1aFnFGRhVWVWoVUAQVR2VnW0YRXldRP28IB0NpVFNWJlhXQhFWDQ5RSxgKWwRZXVoG","queueTime":6,"applicationTime":1444,"atts":"TBtXQQMaH0k=","errorBeacon":"bam.nr-data.net","agent":""}</script></body>
|
||
</html>
|