{"id":2599,"date":"2026-01-13T06:42:17","date_gmt":"2026-01-13T06:42:17","guid":{"rendered":"https:\/\/lightingrecipe.com\/?page_id=2599"},"modified":"2026-01-26T00:51:07","modified_gmt":"2026-01-26T00:51:07","slug":"how-to-measure-light-correctly","status":"publish","type":"page","link":"https:\/\/lightingrecipe.com\/zh\/how-to-measure-light-correctly\/","title":{"rendered":"\u5982\u4f55\u6b63\u78ba\u6e2c\u91cf\u5149\uff1f"},"content":{"rendered":"\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\">\n<figure class=\"wp-block-video alignwide\"><video height=\"1080\" style=\"aspect-ratio: 1920 \/ 1080;\" width=\"1920\" controls src=\"https:\/\/lightingrecipe.com\/wp-content\/uploads\/2026\/01\/How-to-measure-correctly.mp4\"><\/video><\/figure>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\">\n<p class=\"has-black-color has-text-color has-link-color wp-elements-342ff474d1f182897711c5e166bba6b7\" style=\"font-size:15px\">For lighting designers using spectrometers (e.g., devices like the In. Licht Ultra), measurement distance impacts accuracy \u2014 and determines whether you&#8217;re capturing the light source itself, ambient\/task lighting, or human-centric lighting.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-177695d8925210c48aa9b1aa1541b310\"><em><strong>What Are You Measuring?<\/strong><\/em><\/p>\n\n\n\n<p class=\"has-primary-color has-text-color has-link-color has-medium-font-size wp-elements-8677a8a93c4aede05ed990c77590798c\"><strong>1) Direct Light (Source Measurement)<\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-f2fa024769e25a2d46cc999ea1fc14ea\" style=\"font-size:15px\">Key metrics to measure include:<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-0c4e3d418800815b04b82ae4f229d779\" style=\"font-size:15px\">\ud83d\udd39 Correlated Color Temperature (CCT)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-3ff9a9ab31c5d815bc28199ada761d58\" style=\"font-size:15px\">\ud83d\udd39 Spectral Power Distribution (SPD) \u2014 including dominant wavelength (\u03bbd), peak wavelength (\u03bbp), and peak intensity (\u03bbpv)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-686ef80fa404667ab4e68759adbb2b83\" style=\"font-size:15px\">\ud83d\udd39 Color Rendering Metrics \u2014 CRI (Ra and Re), and TM-30 (Rf and Rg)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-eb8a57986f5e22cdb4b8a617bea97f5d\" style=\"font-size:15px\">\ud83d\udd39 Flicker \u2014 flicker frequency, flicker percentage, flicker index, and Stroboscopic Visibility Measure (SVM)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-7e23c4e80cc9772ef7f8a030fd2ebf38\" style=\"font-size:15px\">\ud83d\udd39 SDCM (MacAdam Ellipses)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-30863edd2321d6dc8b6485ce107297c7\" style=\"font-size:15px\">\ud83d\udd39 Chromaticity Coordinates (x, y) and blackbody deviation (Duv)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-155df33a0ef1c3e875f51f18a3baab21\" style=\"font-size:15px\">\ud83d\udd39 Blue Light Hazard Ranking (RG)<\/p>\n\n\n\n<p><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-a2cd36bb615138fb6eb5996000ef065c\"><strong>Room Condition Requirements<\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-cf1fe9d93f2ab618e451a36122483d5e\" style=\"font-size:15px\"><em><strong>1. Dark or Controlled Lighting Environment<\/strong><\/em><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-ed6f2134dca2d64761e03a6534fbef46\" style=\"font-size:15px\">\ud83d\udd39 Ideally, perform measurements in a dark room or one with minimal ambient light to avoid stray light interference.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-942b68986ee24436f786b34f5d6a7e0e\" style=\"font-size:15px\">\ud83d\udd39 If not possible, use black matte surfaces around the test area to reduce reflections.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-19771cc305ec01f41619eb313fa141b7\" style=\"font-size:15px\"><em><strong>2. Avoid Reflective Surfaces<\/strong><\/em><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-3fe2a087e71c9352afd9dbe458d62028\" style=\"font-size:15px\">\ud83d\udd39 Remove or cover any shiny or reflective materials near the light source or sensor.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-b98de0ebb49e934542c4f571df34bb32\" style=\"font-size:15px\"><em><strong>3. Measurement Angle<\/strong><\/em><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-6880dd823212f906b74367a8beb559a7\" style=\"font-size:15px\">\ud83d\udd39 Hold or position the sensor perpendicular to the emitting surface of the light source.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-a4836429ca1983881b5ea88e0ba7bf9e\" style=\"font-size:15px\"><em><strong>4. Measurement Distance<\/strong><\/em><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-e46762e84bff476126a706c10a3cc49b\" style=\"font-size:15px\">\ud83d\udd39 Keep within a 10\u201350 cm range for general light source characterization.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-badadaf288e413f92ba5db30b703c3af\" style=\"font-size:15px\">\ud83d\udd39 The \u201c10\u201350 cm\u201d distance is a commonly used practical guideline in lighting measurement practice, rather than a strict requirement defined by formal standards.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-9941922881331716b9215073d7006142\" style=\"font-size:15px\">\ud83d\udd39 For photobiological safety (Blue Light Hazard Ranking, RG), follow IEC\/EN 62471: For General Lighting Service (GLS) lamps, evaluate safety at the distance where the source emits 500 lux, and no closer than 200 mm.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-2869be8f6c96a1ee52a4cc8941c1ebd1\" style=\"font-size:15px\">\ud83d\udd39 Always maintain a consistent, fixed distance for repeatability.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-0a8e420d7a9618f43b4c131beb536c4c\" style=\"font-size:15px\">\ud83d\udd39 Ensure the sensor\u2019s field of view fully captures the emitting area.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-2e6f36c2eb438e01117a4a226a955193\" style=\"font-size:15px\">\ud83d\udd39 Avoid shadows, obstructions, or ambient stray light during measurements.<\/p>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\">\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-a1fc21956bf78565263b7dddc3ed361e\"><strong>2) Ambient \/ Task Lighting<\/strong><\/p>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\">\n<p class=\"has-black-color has-text-color has-link-color wp-elements-2a8a060525a90a6185f7c2b981c8035c\" style=\"font-size:15px\">This refers to general lighting in a space or light provided for a specific task (like reading or working).<br><br>Key Metrics to measure include:<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-8c199f7d09404b8e9eec57120aa26399\" style=\"font-size:15px\">\ud83d\udd39 Illuminance (lux)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-0c4e3d418800815b04b82ae4f229d779\" style=\"font-size:15px\">\ud83d\udd39 Correlated Color Temperature (CCT)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-de01564ee100e6f23c38c9f0c3d56f0d\" style=\"font-size:15px\">\ud83d\udd39 Color Rendering Metrics \u2013 CRI (Ra and Re), TM-30 (Rf and Rg)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-43dd58a25c37fd3d2a9ef78c8ce2b551\" style=\"font-size:15px\">\ud83d\udd39 Flicker \u2013 Flicker frequency, flicker percentage, flicker index, and Stroboscopic Visibility Measure (SVM)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-61e86a58bf09354602fdf196d2d28532\" style=\"font-size:15px\"><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-a2cd36bb615138fb6eb5996000ef065c\"><strong>Room Condition Requirements<\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-7843db96ac122c1a39dfd6db3d0fca04\" style=\"font-size:15px\">\ud83d\udd39 Ensure normal occupancy conditions (e.g., curtains\/blinds as usual)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-2536b4820e5fde15ae052781030cb095\" style=\"font-size:15px\">\ud83d\udd39 Horizontal Surface (Desk\/Workplane): Height \u2248 0.8 m (typical tabletop)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-4b1426978d0f3ecb21f675c167f33993\" style=\"font-size:15px\">\ud83d\udd39 Vertical Surface (Whiteboard\/Wall Art): Position sensor perpendicular to the wall<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-58737453f207a203f50f0881677c7678\" style=\"font-size:15px\">\ud83d\udd39 Take multiple readings and average the results for accuracy<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-61e86a58bf09354602fdf196d2d28532\" style=\"font-size:15px\"><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-4a1545054e426cc4834a8572c6c17795\"><strong>Based on the WELL Building Standard v2 \u2013 Feature L02: Visual Lighting Design<\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-0e621d28e22800885ac3ae3bc6486e14\" style=\"font-size:15px\">To meet illuminance thresholds, the project must refer to one of the following recognized standards:<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-79ee621d803dac1000f83d33efe42a9c\" style=\"font-size:15px\">\ud83d\udd39 IES Lighting Library \u2013 Lighting Applications Standards Collection<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-e26aa75feb2e1e3d204dd728ae2161e8\" style=\"font-size:15px\">\ud83d\udd39 EN 12464-1:2021 or EN 12464-2:2014<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-21b3275455c185f87ce583af5d62a8d8\" style=\"font-size:15px\">\ud83d\udd39 ISO 8995-1:2002(E) (CIE S 008\/E:2001)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-a82aca3dcf03badbe3adb25276cdce66\" style=\"font-size:15px\">\ud83d\udd39 GB50034-2013<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-69c3944d06f64e6987fb94194c76f20b\" style=\"font-size:15px\">\ud83d\udd39 CIBSE SLL Code for Lighting<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-61e86a58bf09354602fdf196d2d28532\" style=\"font-size:15px\"><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-2c01f55f7b6b1c92f4f070d7e67e4718\"><strong>WELL Performance Verification Conditions<\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-b01b947fd3c82bd2be5143d4642b8624\" style=\"font-size:15px\">To ensure compliance, testing must be conducted under these controlled conditions:<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-3ccd17fec7500c69855c35398b6b95b3\" style=\"font-size:15px\">\ud83d\udd39 Nighttime measurements only \u2013 to eliminate daylight interference<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-ccf16304ba3d7ed4a6c99e3d29ef8b6c\" style=\"font-size:15px\">\ud83d\udd39 Supplemental lighting, if present, must be turned on and positioned on the work surface in typical usage configuration<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-8a8578329182c8315aaa7cd71b11f478\" style=\"font-size:15px\">\ud83d\udd39 Each sample must be taken on the horizontal plane, with the device aperture facing upward<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-37d5f739de3f4f0851d9f74e7e49e073\" style=\"font-size:15px\">\u26a0\ufe0f <em>Important<\/em>: Ensure the shadow of the human does not fall on the device aperture during measurement<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-61e86a58bf09354602fdf196d2d28532\" style=\"font-size:15px\"><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-d323b24746087ac5c6b9b49b4e95ad29\"><strong><em>Tips<\/em>: Use In. Licht Ultra\u2019s PDF Report for WELL Submission<\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-2da824e13bb078498c942337c3b0c515\" style=\"font-size:15px\">In. Licht Ultra automatically generates detailed PDF reports that include all required measurement data. These PDF reports can be used directly as supporting documentation for WELL Performance Verification under Feature L02 and other light-related criteria.<\/p>\n<\/div>\n<\/div>\n\n\n\n<div class=\"wp-block-columns alignwide is-layout-flex wp-container-core-columns-is-layout-9d6595d7 wp-block-columns-is-layout-flex\">\n<div class=\"wp-block-column is-layout-flow wp-block-column-is-layout-flow\" style=\"flex-basis:100%\">\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-a2be552d3194fff18497266e98d2f11e\"><strong><strong>3) <\/strong>Human-Centric Lighting<\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-71fbcd65658b108dcff9772e3f7413ae\" style=\"font-size:15px\"><br>Key Human-Centric Metrics to measure:<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-6273171725588f96e554fa2180895895\" style=\"font-size:15px\">\ud83d\udd39 Circadian Action Factor (CAF)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-ee7e6b6c51455809b1da84bc99b457af\" style=\"font-size:15px\">\ud83d\udd39 Equivalent Melanopic Lux (EML)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-a04db3f0674be4452431f654ff9f428a\" style=\"font-size:15px\">\ud83d\udd39 Melanopic Equivalent Daylight Illuminance (M-EDI)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-7102173dab955601bf88deabce9688f3\" style=\"font-size:15px\">\ud83d\udd39 Scotopic\/Photopic Ratio (S\/P Ratio)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-8ad66c70f2278ffaafe3ae2dca69f259\" style=\"font-size:15px\">\ud83d\udd39 Circadian Stimulus (CS)<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-155df33a0ef1c3e875f51f18a3baab21\" style=\"font-size:15px\">\ud83d\udd39 Blue Light Hazard Ranking (RG)<\/p>\n\n\n\n<p class=\"has-primary-color has-text-color has-link-color has-small-font-size wp-elements-0dcf785fcf2673dba6fd301c3497fdbd\"><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-df0ec991018091e886d01c42d6383370\"><strong>Based on WELL Building Standard v2 \u2013 Feature L03: Circadian Lighting Design<\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-8cd9b589d66a75da20168e5431e2694e\"><em><strong>For Workstations Used During the Daytime<\/strong><\/em><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-fe0b84f951a32e8a1fbccd578cc5b57d\" style=\"font-size:15px\">Electric lighting must achieve the following thresholds for at least 4 hours (beginning no later than noon) at a height of 18 in (\u2248 45 cm) above the work plane in regularly occupied spaces<\/p>\n\n\n\n<p><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-f465155c4e4eaec4aa074f1be8a1f0bb\" style=\"font-size:15px\"><strong>Standard thresholds:<\/strong><\/p>\n\n\n\n<p class=\"has-primary-color has-text-color has-link-color wp-elements-fa4121969b268b120b3fdda6d79ead31\" style=\"font-size:15px\">\ud83d\udd39 \u2265 150 EML [136 M-EDI] (1 point)<\/p>\n\n\n\n<p class=\"has-primary-color has-text-color has-link-color wp-elements-e212b0c3702dd7f62f97bc8680c9ac3b\" style=\"font-size:15px\">\ud83d\udd39 \u2265 275 EML [250 M-EDI] (3 points)<\/p>\n\n\n\n<p class=\"has-primary-color has-text-color has-link-color wp-elements-ce3339325983ca16f8f42def585fac47\" style=\"font-size:15px\"><strong>For thresholds with enhanced daylight:<\/strong><\/p>\n\n\n\n<p class=\"has-primary-color has-text-color has-link-color wp-elements-843502b9307d288487399f6b64f3bb8a\" style=\"font-size:15px\">\ud83d\udd39 \u2265 120 EML [109 M-EDI] + L05 or L06 (1 point)<\/p>\n\n\n\n<p class=\"has-primary-color has-text-color has-link-color wp-elements-3bb1a8e083fb4231b7b5792f8c210c0c\" style=\"font-size:15px\">\ud83d\udd39 \u2265 180 EML [163 M-EDI] + L05 or L06 (3 points)<\/p>\n\n\n\n<p><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-ae3529e6785adffb1ad11eaa19ba536c\"><em><strong>For Residential Units (Dwelling Spaces)<\/strong><\/em><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-a579921686fabac2f9d5e92b08abefc5\" style=\"font-size:15px\">In addition to the thresholds mentioned above, the lighting must be dimmable. If automated, it should dim automatically after 8:00 p.m.<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-a9dfa9bf2641090300a123862cc37606\" style=\"font-size:15px\">Measurements must be taken:<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-967a15f819c801904a63535cf1e2ca68\" style=\"font-size:15px\">\ud83d\udd39In living rooms and kitchens at 55 in (\u2248 140 cm) in the center of the room<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-50fa56447007a864942f9abd8ea900b9\" style=\"font-size:15px\">\ud83d\udd39In studio apartments or guest rooms, also test in the center<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-635fbcc825786f408a3481cea10349d2\" style=\"font-size:15px\">\ud83d\udd39For workstations, at 18 in (\u2248 45 cm) above the work plane<\/p>\n\n\n\n<p><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color has-medium-font-size wp-elements-2c01f55f7b6b1c92f4f070d7e67e4718\"><strong>WELL Performance Verification Conditions<\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-b2af7df9934f3a88e03031cfb9da6fd9\" style=\"font-size:15px\"><strong>WELL v2 (and later)<\/strong>:<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-b0d11dfb9b9c2d52be38023791251ba2\" style=\"font-size:15px\">Take samples at night using only electric light to eliminate daylight influence.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-964cb143999483137dc79e88adcb481b\" style=\"font-size:15px\"><strong>Sampling Position<\/strong>:<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-87086834f616f3fa79ca0779a7846285\" style=\"font-size:15px\">\ud83d\udd39Measure on the vertical plane at 45 cm (18 in) above the work plane, with the aperture facing the direction of gaze<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-87b6cb943d84d97db235ee2c8402ec24\" style=\"font-size:15px\">\ud83d\udd39Light levels must be measured on the vertical plane at eye level to simulate the light entering the eyes<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-65201eac9c79ecac8934ed5242e4a072\" style=\"font-size:15px\">\ud83d\udd39Use a tripod and ensure a stable surface<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-355128ee4b32b97712a302c5e6f20a54\" style=\"font-size:15px\">\ud83d\udd39Avoid casting human shadows on the sensor<\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-970ec2cbf4f37ad8f9273563a55907fa\" style=\"font-size:15px\">\ud83d\udd39Where no working planes are present , take 4 measurements in the center of the space at 140 cm (55 in) in orthogonal directions. The median value of the four measurements constitutes one sample point.<\/p>\n\n\n\n<p><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-62ba3909830931fe6de94f62e9caccd1\" style=\"font-size:15px\"><strong>Reporting &amp; Compliance<\/strong><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-9b0838105f0874a6dec81b9005e9d4b1\" style=\"font-size:15px\">Report the illuminance levels in lux and the spectral power at 5 nm increments from 380 nm to 730 nm.<\/p>\n\n\n\n<p class=\"has-primary-color has-text-color has-link-color has-small-font-size wp-elements-0dcf785fcf2673dba6fd301c3497fdbd\"><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-a78e953dc850f8aedd9390be115ea6d3\" style=\"font-size:15px\"><em><strong>WELL Submission Tip<\/strong><\/em><\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-40c5daa5a63649222273c938a6e88995\" style=\"font-size:15px\">The CSV report generated by In. Licht Ultra includes all required WELL metrics and can be used for WELL Performance Verification.<\/p>\n<\/div>\n<\/div>\n\n\n\n<figure class=\"wp-block-video alignwide\"><video height=\"1080\" style=\"aspect-ratio: 1920 \/ 1080;\" width=\"1920\" controls src=\"https:\/\/lightingrecipe.com\/wp-content\/uploads\/2025\/07\/Measurement-distance.mp4\"><\/video><\/figure>\n\n\n\n<figure class=\"wp-block-video alignwide\"><video height=\"1080\" style=\"aspect-ratio: 1920 \/ 1080;\" width=\"1920\" controls src=\"https:\/\/lightingrecipe.com\/wp-content\/uploads\/2025\/07\/Measurement-distance-part-2.mp4\"><\/video><\/figure>\n","protected":false},"excerpt":{"rendered":"<p>For lighting designers using spectrometers (e.g., devices like the In. Licht Ultra), measurement distance impacts accuracy \u2014 and determines whether you&#8217;re capturing the light source itself, ambient\/task lighting, or human-centric lighting. What Are You Measuring? 1) Direct Light (Source Measurement) Key metrics to measure include: \ud83d\udd39 Correlated Color Temperature (CCT) \ud83d\udd39 Spectral Power Distribution (SPD) \u2014 including dominant wavelength (\u03bbd), peak wavelength (\u03bbp), and peak intensity (\u03bbpv) \ud83d\udd39 Color Rendering Metrics \u2014 CRI (Ra and Re), and TM-30 (Rf and Rg) \ud83d\udd39 Flicker \u2014 flicker frequency, flicker percentage, flicker index, and Stroboscopic Visibility Measure (SVM) \ud83d\udd39 SDCM (MacAdam Ellipses) \ud83d\udd39 Chromaticity Coordinates (x, y) and blackbody deviation (Duv) \ud83d\udd39 Blue Light Hazard Ranking (RG) Room Condition Requirements 1. Dark or Controlled Lighting Environment \ud83d\udd39 Ideally, perform measurements in a dark room or one with minimal ambient light to avoid stray light interference. \ud83d\udd39 If not possible, use black matte surfaces around the test area to reduce reflections. 2. Avoid Reflective Surfaces \ud83d\udd39 Remove or cover any shiny or reflective materials near the light source or sensor. 3. Measurement Angle \ud83d\udd39 Hold or position the sensor perpendicular to the emitting surface of the light source. 4. Measurement Distance \ud83d\udd39 Keep within a 10\u201350 cm range for general light source characterization. \ud83d\udd39 The \u201c10\u201350 cm\u201d distance is a commonly used practical guideline in lighting measurement practice, rather than a strict requirement defined by formal standards. \ud83d\udd39 For photobiological safety (Blue Light Hazard Ranking, RG), follow IEC\/EN 62471: For General Lighting Service (GLS) lamps, evaluate safety at the distance where the source emits 500 lux, and no closer than 200 mm. \ud83d\udd39 Always maintain a consistent, fixed distance for repeatability. \ud83d\udd39 Ensure the sensor\u2019s field of view fully captures the emitting area. \ud83d\udd39 Avoid shadows, obstructions, or ambient stray light during measurements. 2) Ambient \/ Task Lighting This refers to general lighting in a space or light provided for a specific task (like reading or working). Key Metrics to measure include: \ud83d\udd39 Illuminance (lux) \ud83d\udd39 Correlated Color Temperature (CCT) \ud83d\udd39 Color Rendering Metrics \u2013 CRI (Ra and Re), TM-30 (Rf and Rg) \ud83d\udd39 Flicker \u2013 Flicker frequency, flicker percentage, flicker index, and Stroboscopic Visibility Measure (SVM) Room Condition Requirements \ud83d\udd39 Ensure normal occupancy conditions (e.g., curtains\/blinds as usual) \ud83d\udd39 Horizontal Surface (Desk\/Workplane): Height \u2248 0.8 m (typical tabletop) \ud83d\udd39 Vertical Surface (Whiteboard\/Wall Art): Position sensor perpendicular to the wall \ud83d\udd39 Take multiple readings and average the results for accuracy Based on the WELL Building Standard v2 \u2013 Feature L02: Visual Lighting Design To meet illuminance thresholds, the project must refer to one of the following recognized standards: \ud83d\udd39 IES Lighting Library \u2013 Lighting Applications Standards Collection \ud83d\udd39 EN 12464-1:2021 or EN 12464-2:2014 \ud83d\udd39 ISO 8995-1:2002(E) (CIE S 008\/E:2001) \ud83d\udd39 GB50034-2013 \ud83d\udd39 CIBSE SLL Code for Lighting WELL Performance Verification Conditions To ensure compliance, testing must be conducted under these controlled conditions: \ud83d\udd39 Nighttime measurements only \u2013 to eliminate daylight interference \ud83d\udd39 Supplemental lighting, if present, must be turned on and positioned on the work surface in typical usage configuration \ud83d\udd39 Each sample must be taken on the horizontal plane, with the device aperture facing upward \u26a0\ufe0f Important: Ensure the shadow of the human does not fall on the device aperture during measurement Tips: Use In. Licht Ultra\u2019s PDF Report for WELL Submission In. Licht Ultra automatically generates detailed PDF reports that include all required measurement data. These PDF reports can be used directly as supporting documentation for WELL Performance Verification under Feature L02 and other light-related criteria. 3) Human-Centric Lighting Key Human-Centric Metrics to measure: \ud83d\udd39 Circadian Action Factor (CAF) \ud83d\udd39 Equivalent Melanopic Lux (EML) \ud83d\udd39 Melanopic Equivalent Daylight Illuminance (M-EDI) \ud83d\udd39 Scotopic\/Photopic Ratio (S\/P Ratio) \ud83d\udd39 Circadian Stimulus (CS) \ud83d\udd39 Blue Light Hazard Ranking (RG) Based on WELL Building Standard v2 \u2013 Feature L03: Circadian Lighting Design For Workstations Used During the Daytime Electric lighting must achieve the following thresholds for at least 4 hours (beginning no later than noon) at a height of 18 in (\u2248 45 cm) above the work plane in regularly occupied spaces Standard thresholds: \ud83d\udd39 \u2265 150 EML [136 M-EDI] (1 point) \ud83d\udd39 \u2265 275 EML [250 M-EDI] (3 points) For thresholds with enhanced daylight: \ud83d\udd39 \u2265 120 EML [109 M-EDI] + L05 or L06 (1 point) \ud83d\udd39 \u2265 180 EML [163 M-EDI] + L05 or L06 (3 points) For Residential Units (Dwelling Spaces) In addition to the thresholds mentioned above, the lighting must be dimmable. If automated, it should dim automatically after 8:00 p.m. Measurements must be taken: \ud83d\udd39In living rooms and kitchens at 55 in (\u2248 140 cm) in the center of the room \ud83d\udd39In studio apartments or guest rooms, also test in the center \ud83d\udd39For workstations, at 18 in (\u2248 45 cm) above the work plane WELL Performance Verification Conditions WELL v2 (and later): Take samples at night using only electric light to eliminate daylight influence. Sampling Position: \ud83d\udd39Measure on the vertical plane at 45 cm (18 in) above the work plane, with the aperture facing the direction of gaze \ud83d\udd39Light levels must be measured on the vertical plane at eye level to simulate the light entering the eyes \ud83d\udd39Use a tripod and ensure a stable surface \ud83d\udd39Avoid casting human shadows on the sensor \ud83d\udd39Where no working planes are present , take 4 measurements in the center of the space at 140 cm (55 in) in orthogonal directions. The median value of the four measurements constitutes one sample point. Reporting &amp; Compliance Report the illuminance levels in lux and the spectral power at 5 nm increments from 380 nm to 730 nm. WELL Submission Tip The CSV report generated by In. Licht Ultra includes all required WELL metrics and can be used for WELL Performance Verification.<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_glsr_average":0,"_glsr_ranking":0,"_glsr_reviews":0,"footnotes":""},"class_list":["post-2599","page","type-page","status-publish","hentry"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v27.6 - https:\/\/yoast.com\/product\/yoast-seo-wordpress\/ -->\n<title>How to Measure Light Correctly? -<\/title>\n<meta name=\"robots\" content=\"noindex, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<meta property=\"og:locale\" content=\"zh_TW\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"How to Measure Light Correctly? -\" \/>\n<meta property=\"og:description\" content=\"For lighting designers using spectrometers (e.g., devices like the In. Licht Ultra), measurement distance impacts accuracy \u2014 and determines whether you&#8217;re capturing the light source itself, ambient\/task lighting, or human-centric lighting. What Are You Measuring? 1) Direct Light (Source Measurement) Key metrics to measure include: \ud83d\udd39 Correlated Color Temperature (CCT) \ud83d\udd39 Spectral Power Distribution (SPD) \u2014 including dominant wavelength (\u03bbd), peak wavelength (\u03bbp), and peak intensity (\u03bbpv) \ud83d\udd39 Color Rendering Metrics \u2014 CRI (Ra and Re), and TM-30 (Rf and Rg) \ud83d\udd39 Flicker \u2014 flicker frequency, flicker percentage, flicker index, and Stroboscopic Visibility Measure (SVM) \ud83d\udd39 SDCM (MacAdam Ellipses) \ud83d\udd39 Chromaticity Coordinates (x, y) and blackbody deviation (Duv) \ud83d\udd39 Blue Light Hazard Ranking (RG) Room Condition Requirements 1. Dark or Controlled Lighting Environment \ud83d\udd39 Ideally, perform measurements in a dark room or one with minimal ambient light to avoid stray light interference. \ud83d\udd39 If not possible, use black matte surfaces around the test area to reduce reflections. 2. Avoid Reflective Surfaces \ud83d\udd39 Remove or cover any shiny or reflective materials near the light source or sensor. 3. Measurement Angle \ud83d\udd39 Hold or position the sensor perpendicular to the emitting surface of the light source. 4. Measurement Distance \ud83d\udd39 Keep within a 10\u201350 cm range for general light source characterization. \ud83d\udd39 The \u201c10\u201350 cm\u201d distance is a commonly used practical guideline in lighting measurement practice, rather than a strict requirement defined by formal standards. \ud83d\udd39 For photobiological safety (Blue Light Hazard Ranking, RG), follow IEC\/EN 62471: For General Lighting Service (GLS) lamps, evaluate safety at the distance where the source emits 500 lux, and no closer than 200 mm. \ud83d\udd39 Always maintain a consistent, fixed distance for repeatability. \ud83d\udd39 Ensure the sensor\u2019s field of view fully captures the emitting area. \ud83d\udd39 Avoid shadows, obstructions, or ambient stray light during measurements. 2) Ambient \/ Task Lighting This refers to general lighting in a space or light provided for a specific task (like reading or working). Key Metrics to measure include: \ud83d\udd39 Illuminance (lux) \ud83d\udd39 Correlated Color Temperature (CCT) \ud83d\udd39 Color Rendering Metrics \u2013 CRI (Ra and Re), TM-30 (Rf and Rg) \ud83d\udd39 Flicker \u2013 Flicker frequency, flicker percentage, flicker index, and Stroboscopic Visibility Measure (SVM) Room Condition Requirements \ud83d\udd39 Ensure normal occupancy conditions (e.g., curtains\/blinds as usual) \ud83d\udd39 Horizontal Surface (Desk\/Workplane): Height \u2248 0.8 m (typical tabletop) \ud83d\udd39 Vertical Surface (Whiteboard\/Wall Art): Position sensor perpendicular to the wall \ud83d\udd39 Take multiple readings and average the results for accuracy Based on the WELL Building Standard v2 \u2013 Feature L02: Visual Lighting Design To meet illuminance thresholds, the project must refer to one of the following recognized standards: \ud83d\udd39 IES Lighting Library \u2013 Lighting Applications Standards Collection \ud83d\udd39 EN 12464-1:2021 or EN 12464-2:2014 \ud83d\udd39 ISO 8995-1:2002(E) (CIE S 008\/E:2001) \ud83d\udd39 GB50034-2013 \ud83d\udd39 CIBSE SLL Code for Lighting WELL Performance Verification Conditions To ensure compliance, testing must be conducted under these controlled conditions: \ud83d\udd39 Nighttime measurements only \u2013 to eliminate daylight interference \ud83d\udd39 Supplemental lighting, if present, must be turned on and positioned on the work surface in typical usage configuration \ud83d\udd39 Each sample must be taken on the horizontal plane, with the device aperture facing upward \u26a0\ufe0f Important: Ensure the shadow of the human does not fall on the device aperture during measurement Tips: Use In. Licht Ultra\u2019s PDF Report for WELL Submission In. Licht Ultra automatically generates detailed PDF reports that include all required measurement data. These PDF reports can be used directly as supporting documentation for WELL Performance Verification under Feature L02 and other light-related criteria. 3) Human-Centric Lighting Key Human-Centric Metrics to measure: \ud83d\udd39 Circadian Action Factor (CAF) \ud83d\udd39 Equivalent Melanopic Lux (EML) \ud83d\udd39 Melanopic Equivalent Daylight Illuminance (M-EDI) \ud83d\udd39 Scotopic\/Photopic Ratio (S\/P Ratio) \ud83d\udd39 Circadian Stimulus (CS) \ud83d\udd39 Blue Light Hazard Ranking (RG) Based on WELL Building Standard v2 \u2013 Feature L03: Circadian Lighting Design For Workstations Used During the Daytime Electric lighting must achieve the following thresholds for at least 4 hours (beginning no later than noon) at a height of 18 in (\u2248 45 cm) above the work plane in regularly occupied spaces Standard thresholds: \ud83d\udd39 \u2265 150 EML [136 M-EDI] (1 point) \ud83d\udd39 \u2265 275 EML [250 M-EDI] (3 points) For thresholds with enhanced daylight: \ud83d\udd39 \u2265 120 EML [109 M-EDI] + L05 or L06 (1 point) \ud83d\udd39 \u2265 180 EML [163 M-EDI] + L05 or L06 (3 points) For Residential Units (Dwelling Spaces) In addition to the thresholds mentioned above, the lighting must be dimmable. If automated, it should dim automatically after 8:00 p.m. Measurements must be taken: \ud83d\udd39In living rooms and kitchens at 55 in (\u2248 140 cm) in the center of the room \ud83d\udd39In studio apartments or guest rooms, also test in the center \ud83d\udd39For workstations, at 18 in (\u2248 45 cm) above the work plane WELL Performance Verification Conditions WELL v2 (and later): Take samples at night using only electric light to eliminate daylight influence. Sampling Position: \ud83d\udd39Measure on the vertical plane at 45 cm (18 in) above the work plane, with the aperture facing the direction of gaze \ud83d\udd39Light levels must be measured on the vertical plane at eye level to simulate the light entering the eyes \ud83d\udd39Use a tripod and ensure a stable surface \ud83d\udd39Avoid casting human shadows on the sensor \ud83d\udd39Where no working planes are present , take 4 measurements in the center of the space at 140 cm (55 in) in orthogonal directions. The median value of the four measurements constitutes one sample point. Reporting &amp; Compliance Report the illuminance levels in lux and the spectral power at 5 nm increments from 380 nm to 730 nm. WELL Submission Tip The CSV report generated by In. Licht Ultra includes all required WELL metrics and can be used for WELL Performance Verification.\" \/>\n<meta property=\"og:url\" content=\"https:\/\/lightingrecipe.com\/zh\/how-to-measure-light-correctly\/\" \/>\n<meta property=\"article:modified_time\" content=\"2026-01-26T00:51:07+00:00\" \/>\n<meta name=\"twitter:card\" content=\"summary_large_image\" \/>\n<meta name=\"twitter:label1\" content=\"\u9810\u4f30\u95b1\u8b80\u6642\u9593\" \/>\n\t<meta name=\"twitter:data1\" content=\"5 \u5206\u9418\" \/>\n<script type=\"application\/ld+json\" class=\"yoast-schema-graph\">{\"@context\":\"https:\\\/\\\/schema.org\",\"@graph\":[{\"@type\":\"WebPage\",\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/how-to-measure-light-correctly\\\/\",\"url\":\"https:\\\/\\\/lightingrecipe.com\\\/how-to-measure-light-correctly\\\/\",\"name\":\"How to Measure Light Correctly? -\",\"isPartOf\":{\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/#website\"},\"datePublished\":\"2026-01-13T06:42:17+00:00\",\"dateModified\":\"2026-01-26T00:51:07+00:00\",\"breadcrumb\":{\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/how-to-measure-light-correctly\\\/#breadcrumb\"},\"inLanguage\":\"zh-TW\",\"potentialAction\":[{\"@type\":\"ReadAction\",\"target\":[\"https:\\\/\\\/lightingrecipe.com\\\/how-to-measure-light-correctly\\\/\"]}]},{\"@type\":\"BreadcrumbList\",\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/how-to-measure-light-correctly\\\/#breadcrumb\",\"itemListElement\":[{\"@type\":\"ListItem\",\"position\":1,\"name\":\"Home\",\"item\":\"https:\\\/\\\/lightingrecipe.com\\\/\"},{\"@type\":\"ListItem\",\"position\":2,\"name\":\"How to Measure Light Correctly?\"}]},{\"@type\":\"WebSite\",\"@id\":\"https:\\\/\\\/lightingrecipe.com\\\/#website\",\"url\":\"https:\\\/\\\/lightingrecipe.com\\\/\",\"name\":\"\",\"description\":\"\",\"potentialAction\":[{\"@type\":\"SearchAction\",\"target\":{\"@type\":\"EntryPoint\",\"urlTemplate\":\"https:\\\/\\\/lightingrecipe.com\\\/?s={search_term_string}\"},\"query-input\":{\"@type\":\"PropertyValueSpecification\",\"valueRequired\":true,\"valueName\":\"search_term_string\"}}],\"inLanguage\":\"zh-TW\"}]}<\/script>\n<!-- \/ Yoast SEO plugin. -->","yoast_head_json":{"title":"How to Measure Light Correctly? -","robots":{"index":"noindex","follow":"follow","max-snippet":"max-snippet:-1","max-image-preview":"max-image-preview:large","max-video-preview":"max-video-preview:-1"},"og_locale":"zh_TW","og_type":"article","og_title":"How to Measure Light Correctly? -","og_description":"For lighting designers using spectrometers (e.g., devices like the In. Licht Ultra), measurement distance impacts accuracy \u2014 and determines whether you&#8217;re capturing the light source itself, ambient\/task lighting, or human-centric lighting. What Are You Measuring? 1) Direct Light (Source Measurement) Key metrics to measure include: \ud83d\udd39 Correlated Color Temperature (CCT) \ud83d\udd39 Spectral Power Distribution (SPD) \u2014 including dominant wavelength (\u03bbd), peak wavelength (\u03bbp), and peak intensity (\u03bbpv) \ud83d\udd39 Color Rendering Metrics \u2014 CRI (Ra and Re), and TM-30 (Rf and Rg) \ud83d\udd39 Flicker \u2014 flicker frequency, flicker percentage, flicker index, and Stroboscopic Visibility Measure (SVM) \ud83d\udd39 SDCM (MacAdam Ellipses) \ud83d\udd39 Chromaticity Coordinates (x, y) and blackbody deviation (Duv) \ud83d\udd39 Blue Light Hazard Ranking (RG) Room Condition Requirements 1. Dark or Controlled Lighting Environment \ud83d\udd39 Ideally, perform measurements in a dark room or one with minimal ambient light to avoid stray light interference. \ud83d\udd39 If not possible, use black matte surfaces around the test area to reduce reflections. 2. Avoid Reflective Surfaces \ud83d\udd39 Remove or cover any shiny or reflective materials near the light source or sensor. 3. Measurement Angle \ud83d\udd39 Hold or position the sensor perpendicular to the emitting surface of the light source. 4. Measurement Distance \ud83d\udd39 Keep within a 10\u201350 cm range for general light source characterization. \ud83d\udd39 The \u201c10\u201350 cm\u201d distance is a commonly used practical guideline in lighting measurement practice, rather than a strict requirement defined by formal standards. \ud83d\udd39 For photobiological safety (Blue Light Hazard Ranking, RG), follow IEC\/EN 62471: For General Lighting Service (GLS) lamps, evaluate safety at the distance where the source emits 500 lux, and no closer than 200 mm. \ud83d\udd39 Always maintain a consistent, fixed distance for repeatability. \ud83d\udd39 Ensure the sensor\u2019s field of view fully captures the emitting area. \ud83d\udd39 Avoid shadows, obstructions, or ambient stray light during measurements. 2) Ambient \/ Task Lighting This refers to general lighting in a space or light provided for a specific task (like reading or working). Key Metrics to measure include: \ud83d\udd39 Illuminance (lux) \ud83d\udd39 Correlated Color Temperature (CCT) \ud83d\udd39 Color Rendering Metrics \u2013 CRI (Ra and Re), TM-30 (Rf and Rg) \ud83d\udd39 Flicker \u2013 Flicker frequency, flicker percentage, flicker index, and Stroboscopic Visibility Measure (SVM) Room Condition Requirements \ud83d\udd39 Ensure normal occupancy conditions (e.g., curtains\/blinds as usual) \ud83d\udd39 Horizontal Surface (Desk\/Workplane): Height \u2248 0.8 m (typical tabletop) \ud83d\udd39 Vertical Surface (Whiteboard\/Wall Art): Position sensor perpendicular to the wall \ud83d\udd39 Take multiple readings and average the results for accuracy Based on the WELL Building Standard v2 \u2013 Feature L02: Visual Lighting Design To meet illuminance thresholds, the project must refer to one of the following recognized standards: \ud83d\udd39 IES Lighting Library \u2013 Lighting Applications Standards Collection \ud83d\udd39 EN 12464-1:2021 or EN 12464-2:2014 \ud83d\udd39 ISO 8995-1:2002(E) (CIE S 008\/E:2001) \ud83d\udd39 GB50034-2013 \ud83d\udd39 CIBSE SLL Code for Lighting WELL Performance Verification Conditions To ensure compliance, testing must be conducted under these controlled conditions: \ud83d\udd39 Nighttime measurements only \u2013 to eliminate daylight interference \ud83d\udd39 Supplemental lighting, if present, must be turned on and positioned on the work surface in typical usage configuration \ud83d\udd39 Each sample must be taken on the horizontal plane, with the device aperture facing upward \u26a0\ufe0f Important: Ensure the shadow of the human does not fall on the device aperture during measurement Tips: Use In. Licht Ultra\u2019s PDF Report for WELL Submission In. Licht Ultra automatically generates detailed PDF reports that include all required measurement data. These PDF reports can be used directly as supporting documentation for WELL Performance Verification under Feature L02 and other light-related criteria. 3) Human-Centric Lighting Key Human-Centric Metrics to measure: \ud83d\udd39 Circadian Action Factor (CAF) \ud83d\udd39 Equivalent Melanopic Lux (EML) \ud83d\udd39 Melanopic Equivalent Daylight Illuminance (M-EDI) \ud83d\udd39 Scotopic\/Photopic Ratio (S\/P Ratio) \ud83d\udd39 Circadian Stimulus (CS) \ud83d\udd39 Blue Light Hazard Ranking (RG) Based on WELL Building Standard v2 \u2013 Feature L03: Circadian Lighting Design For Workstations Used During the Daytime Electric lighting must achieve the following thresholds for at least 4 hours (beginning no later than noon) at a height of 18 in (\u2248 45 cm) above the work plane in regularly occupied spaces Standard thresholds: \ud83d\udd39 \u2265 150 EML [136 M-EDI] (1 point) \ud83d\udd39 \u2265 275 EML [250 M-EDI] (3 points) For thresholds with enhanced daylight: \ud83d\udd39 \u2265 120 EML [109 M-EDI] + L05 or L06 (1 point) \ud83d\udd39 \u2265 180 EML [163 M-EDI] + L05 or L06 (3 points) For Residential Units (Dwelling Spaces) In addition to the thresholds mentioned above, the lighting must be dimmable. If automated, it should dim automatically after 8:00 p.m. Measurements must be taken: \ud83d\udd39In living rooms and kitchens at 55 in (\u2248 140 cm) in the center of the room \ud83d\udd39In studio apartments or guest rooms, also test in the center \ud83d\udd39For workstations, at 18 in (\u2248 45 cm) above the work plane WELL Performance Verification Conditions WELL v2 (and later): Take samples at night using only electric light to eliminate daylight influence. Sampling Position: \ud83d\udd39Measure on the vertical plane at 45 cm (18 in) above the work plane, with the aperture facing the direction of gaze \ud83d\udd39Light levels must be measured on the vertical plane at eye level to simulate the light entering the eyes \ud83d\udd39Use a tripod and ensure a stable surface \ud83d\udd39Avoid casting human shadows on the sensor \ud83d\udd39Where no working planes are present , take 4 measurements in the center of the space at 140 cm (55 in) in orthogonal directions. The median value of the four measurements constitutes one sample point. Reporting &amp; Compliance Report the illuminance levels in lux and the spectral power at 5 nm increments from 380 nm to 730 nm. WELL Submission Tip The CSV report generated by In. Licht Ultra includes all required WELL metrics and can be used for WELL Performance Verification.","og_url":"https:\/\/lightingrecipe.com\/zh\/how-to-measure-light-correctly\/","article_modified_time":"2026-01-26T00:51:07+00:00","twitter_card":"summary_large_image","twitter_misc":{"\u9810\u4f30\u95b1\u8b80\u6642\u9593":"5 \u5206\u9418"},"schema":{"@context":"https:\/\/schema.org","@graph":[{"@type":"WebPage","@id":"https:\/\/lightingrecipe.com\/how-to-measure-light-correctly\/","url":"https:\/\/lightingrecipe.com\/how-to-measure-light-correctly\/","name":"How to Measure Light Correctly? -","isPartOf":{"@id":"https:\/\/lightingrecipe.com\/#website"},"datePublished":"2026-01-13T06:42:17+00:00","dateModified":"2026-01-26T00:51:07+00:00","breadcrumb":{"@id":"https:\/\/lightingrecipe.com\/how-to-measure-light-correctly\/#breadcrumb"},"inLanguage":"zh-TW","potentialAction":[{"@type":"ReadAction","target":["https:\/\/lightingrecipe.com\/how-to-measure-light-correctly\/"]}]},{"@type":"BreadcrumbList","@id":"https:\/\/lightingrecipe.com\/how-to-measure-light-correctly\/#breadcrumb","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https:\/\/lightingrecipe.com\/"},{"@type":"ListItem","position":2,"name":"How to Measure Light Correctly?"}]},{"@type":"WebSite","@id":"https:\/\/lightingrecipe.com\/#website","url":"https:\/\/lightingrecipe.com\/","name":"","description":"","potentialAction":[{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https:\/\/lightingrecipe.com\/?s={search_term_string}"},"query-input":{"@type":"PropertyValueSpecification","valueRequired":true,"valueName":"search_term_string"}}],"inLanguage":"zh-TW"}]}},"jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/pages\/2599","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/comments?post=2599"}],"version-history":[{"count":3,"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/pages\/2599\/revisions"}],"predecessor-version":[{"id":2721,"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/pages\/2599\/revisions\/2721"}],"wp:attachment":[{"href":"https:\/\/lightingrecipe.com\/zh\/wp-json\/wp\/v2\/media?parent=2599"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}