Letter regarding the possible contents of and functioning of the glass electrode in the first pH meter models.

Arnold Beckman invented his first pH meter in 1934 at the request of Glenn Joseph, a chemist from the…

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…

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…

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…

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…

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…

One of the earliest inquiries into using one of Arnold Beckman's newly invented pH meters.

Arnold Beckman invented his first pH meter in 1934 at the request of a chemist from the California citrus industry, who needed…

Response to an earlier letter from Dr. Duschak, asking if Dr. Beckman's new "acidimeter" would be appropriate for determining the pH of vegetable juices. Beckman describes some of the recent changes to the instrument,…

Duschak comments on the price of the pH meter (high, but in line with comparable instruments) and inquires whether or not the "acidimeter" could be sold again after his project is finished.

Arnold Beckman invented his…

The contract outlines details (including salary, confidentiality, and intellectual property rights) of Howard Cary's work for Arnold Beckman.

Howard Cary (1908-1991) was a Caltech-educated engineer who joined National…

Lyons gives Beckman advice about personnel decisions and discusses early sales of the "acidimeter."

Dr. Arnold O. Beckman (1900-2004) invented the first commercially successful electric pH meter in 1934 and thus began…

Though unsigned, context indicates that this letter was written by Beckman.

Dr. Arnold O. Beckman (1900-2004) invented the first commercially successful electric pH meter in 1934 and thus began a long career…

Letter to Arnold O. Beckman about the early stages of planning marketing and distribution for the pH meter. The National Postal Meter Company on the letterhead was one of Arnold Beckman's first employers, when they…

In this letter, Beckman discusses acidimeter production, personnel issues, patent applications, and the naming of the instrument.

Dr. Arnold O. Beckman (1900-2004) invented the first commercially successful electric pH…

This letter includes discussion of personnel issues and policies. Lyons expresses approval for the "Beckman Acidimeter" name.

Dr. Arnold O. Beckman (1900-2004) invented the first commercially successful electric pH…

From an unknown author at the Braun Corporation (and carbon copied to its president, J.A. Hartley). The author wants Aldoph Coors (the brewing magnate) to meet Arnold O. Beckman during Beckman's trip to promote his new…

Lyons writes to Beckman during Beckman's travels around the United States to market his new "acidimeter." This letter in particular mentions the orders rolling in following the first advertisement for the pH meter and…

Regarding Beckman's business travels to meet with a potential acidimeter distributor, A. S. Aloe Co., and Drs. Ball and Rodewald at the Washington University in St. Louis.

Dr. Arnold O. Beckman (1900-2004) invented the…

Regarding Beckman's business travels to meet with two potential acidimeter distributors, Central Scientific Co. and Sargent Co.

Dr. Arnold O. Beckman (1900-2004) invented the first commercially successful electric pH…

Beckman thanks Evans for his hospitality during a trip to Denver, Colorado to sell the new pH meter and hopes that Evans will become a distributor for the instrument. Beckman's stops in Denver included Coors Porcelain…

This letter from Arnold Beckman was sent during his 1935 trip around the United States to promote and secure distributors for his new pH meter (or "acidimeter") in 1935. Beckman reports on the enthusiasm of both…

Anderson writes from National Technical Labatories to Arnold Beckman, providing him with an update about "acidimeter" production and pre-sales interest while Beckman is away in New York City. He notes that the first…

The letter discusses shipment of wheat germ, expenses; demonstrations of the acidimeter at the Pennsylvania General Hospital, University of Pennsylvania, the Department of Agriculture, and the Bureau of Standards;…

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…

The letter touches on Arthur Noyes's medical condition and discusses problems with an instrument demonstration caused by residue in electrodes. Beckman was a friend and colleague of Dr. Noyes and was seeking medical…