{"id":17324,"date":"2023-05-21T15:25:16","date_gmt":"2023-05-21T22:25:16","guid":{"rendered":"https:\/\/www.vernier.com\/til\/?p=17324"},"modified":"2025-07-18T10:28:59","modified_gmt":"2025-07-18T17:28:59","slug":"which-par-sensor-par-bta-do-i-have","status":"publish","type":"post","link":"https:\/\/www.vernier.com\/til\/17324","title":{"rendered":"Which Apogee sensor head does my PAR Sensor have?"},"content":{"rendered":"

Use the picture below to determine which Apogee sensor your PAR Sensor<\/a> (PAR-BTA<\/nobr>) has.<\/p>\n

Starting in May 2023, all Vernier PAR sensors, including Go Direct®<\/sup> PAR (Photosynthetically Active Radiation)<\/a> (GDX-PAR<\/nobr>), use the Apogee SQ-100x sensor head that is attached to the main cable using a P68-rated stainless-steel marine grade (M8) connector (see red arrow in picture below). This connector is located 25 cm from the sensor head. <\/p>\n

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If your PAR-BTA sensor does not have a metal (M8) connector then it is the older PAR Sensor that has an apogee SQ-110 sensor head calibrated for use in sunlight. The older sensor heads have different spectral response profiles than the new sensor heads (see graph below).<\/p>\n

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The graph shows the spectral response profile of the older Apogee SQ-110 sensor head (gray line) compared to the new SQ-100X sensor head (green line). An idealized PPFD response (dotted black line) is presented for comparison.<\/p>\n<\/div>\n<\/div>\n

Note:<\/strong> The newer PAR sensors use different correction factors when measuring PPFD under water, under certain artificial lights, and in certain field conditions. For more information, see Can I use Vernier PAR sensors with electric lights? When do I need to use a Correction Factor?<\/a>.<\/p>\n

If you need the user manual for the older PAR sensor, click here<\/a>.<\/p>","protected":false},"excerpt":{"rendered":"

Use the picture below to determine which Apogee sensor your has. Starting in May 2023, all Vernier PAR sensors, including , use the Apogee SQ-100x…<\/p>\n","protected":false},"author":8971,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[],"tags":[1487,5220],"class_list":["post-17324","post","type-post","status-publish","format-standard","hentry","tag-par","tag-par-bta-par-bta"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts\/17324","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\/8971"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/comments?post=17324"}],"version-history":[{"count":0,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts\/17324\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/media?parent=17324"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/categories?post=17324"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/tags?post=17324"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}