Color advertisement for the Pocket pH Meter, which was first sold in 1956. The main selling point of this model was its portability, meaning that pH readings could be taken in the field or on site, instead of requiring that samples be transported back to a laboratory where a stationary instrument could be used.

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.