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 - Presentation of Beckman pH Meters ID - rj430460z AV - Beckman Historical Collection, Box 55, Folder 141 VL - Beckman Historical Collection, Box 55, Folder 141 AN - Beckman Historical Collection, Box 55, Folder 141 UR - https://digital.sciencehistory.org/works/rj430460z KW - Hydrogen-ion concentration--Measurement--Instruments KW - Scientific apparatus and instruments KW - Beckman Instruments, Inc. LA - ER -