TY - MANSCPT DB - Science History Institute DP - Science History Institute M2 - Courtesy of Science History Institute. Rights: In Copyright - Rights-holder(s) Unlocatable or Unidentifiable TI - Various models of Beckman pH meters ID - 5138jf27h AU - Hesketh, Dean D. DA - 1960/// YR - 1960 AV - Beckman Historical Collection, Box 86 VL - Beckman Historical Collection, Box 86 AN - Beckman Historical Collection, Box 86 UR - https://digital.sciencehistory.org/works/5138jf27h AB - This group photograph appears to include Models G, N, N2, 72, and Pocket pH meters. 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. KW - Hydrogen-ion concentration--Measurement--Instruments KW - Scientific apparatus and instruments KW - Hydrogen-ion concentration KW - Beckman Instruments, Inc. LA - ER -