{"id":3554,"date":"2016-09-20T16:23:25","date_gmt":"2016-09-20T23:23:25","guid":{"rendered":""},"modified":"2026-03-25T13:42:43","modified_gmt":"2026-03-25T20:42:43","slug":"3554","status":"publish","type":"post","link":"https:\/\/www.vernier.com\/til\/3554","title":{"rendered":"Why is my Optical DO Probe reading a negative value?"},"content":{"rendered":"<p>If the ODO is reading a negative value, follow the process to reset the calibration. <a href=\"\/til\/3345\/\">How do I reset the calibration on the Optical DO Probe?<\/a><\/p>\n<p class=\"wp-block-paragraph\">If resetting the calibration does not work and your <a href=\"\/product\/vernier-optical-do-probe\/\">Vernier Optical DO Probe<\/a> (<nobr>ODO-BTA<\/nobr>) is was purchased before 2021, sadly it cannot be repaired.<\/p>\n<p class=\"wp-block-paragraph\">If you are unsure of when it was purchased please contact Vernier Support and we will look into it for you.  <\/p>","protected":false},"excerpt":{"rendered":"<p>If the ODO is reading a negative value, follow the process to reset the calibration. If resetting the calibration does not work and your is&#8230;<\/p>\n","protected":false},"author":41204,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[],"tags":[298,6025,4972,1798],"class_list":["post-3554","post","type-post","status-publish","format-standard","hentry","tag-dissolved-oxygen","tag-negative","tag-odo","tag-odo-bta"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts\/3554","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\/41204"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/comments?post=3554"}],"version-history":[{"count":0,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/posts\/3554\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/media?parent=3554"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/categories?post=3554"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vernier.com\/til\/wp-json\/wp\/v2\/tags?post=3554"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}