The quinhydrone electrode in this instrument was an alternative to Beckman's glass electrode. Quinhydrone electrodes are not reliable at measuring a pH greater than 8, at measuring solutions with strong oxidizing or reducing agents, or solutions containing proteins or high levels of salts.
Arnold Beckman invented his first pH meter in 1934 at the request of a chemist from the California citrus industry, who needed an accurate way to measure the acidity of his product. The resulting instrument kicked off rapid development not only of Beckman Instruments, Inc. but also of the electronic scientific instrument industry.
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|Original file type||TIFF|
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