There are chemical test kits that are accurate to measure dissolved oxygen depending on how well you collect the sample. The way you collect the sample can diffuse more oxygen into the sample. Here are two good quality DO test kits.

https://pentairaes.com/lamotte-dissolved-oxygen-test-kit.html?msclkid=04b917a4cd621582951e4df43574b54c&utm_source=bing&utm_medium=cpc&utm_campaign=(ROI)%20Pentair%20AES%20-%20Shopping%20-%20Desktop&utm_term=4584826048954002&utm_content=Water%20Quality%20Testing

http://www.lamotte.com/en/aquarium-fish-farming/individual-test-kits/5860-01.html


http://www.forestry-suppliers.com/product_pages/products.php?mi=33281&itemnum=78052&redir=Y

There may be good simple chemical test kits available at good aquarium supply stores. Research testing kits before purchasing them, as some are known to produce flawed results when used in conjunction with other chemicals and water treatments.

I learned and used the standard chemical method in college and later kits that were similar to the chemical method for measuring DO. The name for the chemical method for measuring DO is called the Winkler Method. The Winkler method is/was used as a standard test to check the accuracy of a DO meter.
Full description of the Winkler method.
https://serc.carleton.edu/microbelife/research_methods/environ_sampling/oxygen.html

Last edited by Bill Cody; 01/06/18 11:24 AM.

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