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 the patent process.The National Postal Meter Company on the letterhead was one of Arnold Beckman's first employers, when they hired him to develop a new kind of ink for postal meters. That project grew into National Inking Appliance Company (a subsidiary of NPMC) in 1934, which became the standalone National Technical Laboratories in 1935. NTL was the first company Beckman owned and it eventually grew into Beckman Instruments, Inc.

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.