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

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

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

…The Century SS-1 pH meter was released in 1973. Arnold Beckman invented his first pH meter in 1934 at the request…

…The Model 4500 Digital pH Meter was released in 1973. Arnold Beckman invented his first pH meter in 1934 at the request…

…, and Φ12. Arnold Beckman invented his first pH meter in 1934 at the request of a chemist from the California citrus industry, who needed an…

…Polaroid photograph of what seems to be a Model G pH meter in a clear glass case as part of an exhibit or display. Arnold Beckman invented his first pH meter in 1934 at the request of a chemist from the California citrus industry, who needed an …with its glass electrode was renamed the Model G pH meter in 1937 and produced on a larger scale by Beckman’s company, National Technical Laboratories…

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

…invented the first commercially successful electric pH meter in 1934 and thus began a long career manufacturing scientific and medical instruments …

…invented the first commercially successful electric pH meter in 1934 and thus began a long career manufacturing scientific and medical instruments …

…Howard Cary (who had previously been involved in pH meter development), NTL produced its first DU Spectrophotometer prototype in 1940. This first…

…Howard Cary (who had previously been involved in pH meter development), NTL produced its first DU Spectrophotometer prototype in 1940. This first…

…Howard Cary (who had previously been involved in pH meter development), NTL produced its first DU Spectrophotometer in 1940. This first Model A …

…Howard Cary (who had previously been involved in pH meter development), NTL produced its first DU Spectrophotometer prototype in 1940. This first…