Advertisement featuring an image of a man kneeling in a field looking at the reading on a Beckman Pocket pH Meter. This model of pH meter was first marketed by Beckman Instruments in 1956, and as this advertisement shows, its portability and small size were the main selling points.

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.