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 - Beckman Φ line of pH meters ID - 5d86p033n DA - 1980/// YR - 1980 AV - Beckman Historical Collection, Box 80 VL - Beckman Historical Collection, Box 80 AN - Beckman Historical Collection, Box 80 UR - https://digital.sciencehistory.org/works/5d86p033n AB - The models in this image are the Φ10, Φ11, 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 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 - Beckman Instruments, Inc. LA - ER -