{"id":68,"date":"2007-07-12T11:42:31","date_gmt":"2007-07-12T15:42:31","guid":{"rendered":"http:\/\/www.washingtonwinemaker.com\/blog\/2007\/07\/12\/calibrating-a-ph-meter\/"},"modified":"2007-07-12T11:42:31","modified_gmt":"2007-07-12T15:42:31","slug":"calibrating-a-ph-meter","status":"publish","type":"post","link":"https:\/\/washingtonwinemaker.com\/blog\/2007\/07\/12\/calibrating-a-ph-meter\/","title":{"rendered":"Calibrating A pH Meter"},"content":{"rendered":"<p><img decoding=\"async\" style=\"float:right; margin-left:1em;\" src=\"\/pic\/20070711 - beginning first calibration.jpg\" alt=\"pH meter, in a champagne glass about a quarter full of 6.86 buffered solution, reads a pH of 6.17 at 31.4 Celsius.\" title=\"Beginning pH Meter's First Calibration\" \/>To work properly, a pH meter must be calibrated. You do this by preparing (or buying) <a href=\"http:\/\/www.washingtonwinemaker.com\/blog\/2007\/11\/07\/calibrating-a-ph-meter-buffer-solution\/\" title=\"More About pH Buffers\">buffered solutions<\/a> of known pH and testing the meter against them. My meter uses a two point calibration. It works by immersing the meter in the first buffer solution (pH 6.86 in this case) then reading the pH and temperature values.<\/p>\n<p>You turn a calibration screw until the meter shows the correct pH for the given temperature (the bottle of buffer solution has a table of temperature and pH values). The pH of the &#8220;6.86&#8221; buffer solution that I&#8217;m using is 6.85 at 30 Celsius, the closest temperature on the correction table to 31.4, so I turned the calibration screw to 6.85. That&#8217;s the first &#8220;point&#8221; of the two point calibration process. The second step is exactly the same but with a different buffer solution (ph 4).<\/p>\n<p>I&#8217;ll use my new toy &#8211; um, important scientific instrument &#8211; along with my simple acid titration kit to analyze my <a href=\"http:\/\/www.washingtonwinemaker.com\/blog\/2007\/06\/08\/oregano-wine\/\">oregano wine<\/a>. Fermentation has been very slow and I&#8217;m afraid the pH of the wine has fallen so low that it&#8217;s inhibiting the yeast.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>To work well, pH meters must be calibrated. Here I explain what that means and how to do it.<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[13,21,23],"tags":[48],"class_list":["post-68","post","type-post","status-publish","format-standard","hentry","category-equipment","category-maintenance-and-cleaning","category-measurement-testing","tag-nad"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/washingtonwinemaker.com\/blog\/wp-json\/wp\/v2\/posts\/68","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/washingtonwinemaker.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/washingtonwinemaker.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/washingtonwinemaker.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/washingtonwinemaker.com\/blog\/wp-json\/wp\/v2\/comments?post=68"}],"version-history":[{"count":0,"href":"https:\/\/washingtonwinemaker.com\/blog\/wp-json\/wp\/v2\/posts\/68\/revisions"}],"wp:attachment":[{"href":"https:\/\/washingtonwinemaker.com\/blog\/wp-json\/wp\/v2\/media?parent=68"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/washingtonwinemaker.com\/blog\/wp-json\/wp\/v2\/categories?post=68"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/washingtonwinemaker.com\/blog\/wp-json\/wp\/v2\/tags?post=68"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}