{"id":413,"date":"2012-09-20T00:18:18","date_gmt":"2012-09-20T07:18:18","guid":{"rendered":""},"modified":"2024-09-05T09:07:35","modified_gmt":"2024-09-05T16:07:35","slug":"413","status":"publish","type":"post","link":"https:\/\/www.vernier.com\/til\/413","title":{"rendered":"What is the conversion from lux to W\/cm<sup>2<\/sup> ?"},"content":{"rendered":"<p class=\"wp-block-paragraph\">There is no exact conversion factor.<\/p>\n<p class=\"wp-block-paragraph\">The problem is that lux and W\/cm<sup>2<\/sup> are not simply different units, rather they are units for different measurements.<\/p>\n<p class=\"wp-block-paragraph\">mW\/cm<sup>2<\/sup> is a unit for irradiance (energy falling on a surface) and lux is a photometric unit for illuminance (visible light falling on a surface). The <a href=\"\/product\/light-sensor\/\">Light Sensor<\/a> (<nobr>LS-BTA<\/nobr>) and the light sensor in the <a href=\"\/product\/go-direct-light-and-color-sensor\/\">Go Direct<sup>&reg;<\/sup> Light and Color Sensor<\/a> (<nobr>GDX-LC<\/nobr>) are optimized for the wavelengths seen as visible light, weighted much like the human eye (see the Light Sensor information sheet). When measuring lux, you are measuring this visible brightness.<\/p>\n<p class=\"wp-block-paragraph\">On the other hand, W\/cm<sup>2<\/sup> is a measurement of absorbed energy, or irradiance. This may happen from a much broader spectrum.<\/p>\n<p class=\"wp-block-paragraph\">There is no single conversion factor between lx and W\/m<sup>2<\/sup>, as there is a different conversion factor for every wavelength. The spectral composition of light would be required to estimate a conversion factor.<\/p>\n<p class=\"wp-block-paragraph\">Our <a href=\"\/product\/go-direct-pyranometer\/\">Go Direct\u00ae Pyranometer<\/a> (<nobr>GDX-PYR<\/nobr>) and <a href=\"\/product\/pyranometer\/\">Pyranometer<\/a> (<nobr>PYR-BTA<\/nobr>) sensors measure irradiance.<\/p>","protected":false},"excerpt":{"rendered":"<p>There is no exact conversion factor. The problem is that lux and W\/cm2 are not simply different units, rather they are units for different measurements&#8230;.<\/p>\n","protected":false},"author":8976,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[],"tags":[],"class_list":["post-413","post","type-post","status-publish","format-standard","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts\/413","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/users\/8976"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/comments?post=413"}],"version-history":[{"count":0,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts\/413\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/media?parent=413"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/categories?post=413"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/tags?post=413"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}