pH Meter
name: label: maker
content: National Technical Laboratories
notes: label: Description
content: A pH meter measures the acidity of aqueous solutions. When asked about a meter suitable for testing citrus fruit, Arnold Beckman, a young chemist at the California Institute of Technology, designed one with glass electrodes, and introduced a prototype at the American Chemical Society meeting in 1935. Most instrument dealers were deterred by the cost (about $195), but with encouragement from Arthur H. Thomas, in Philadelphia, Beckman established the National Technical Laboratories in Pasadena, and began production. The firm became Arnold O. Beckman, Inc. in the 1940s, and later Beckman Instruments, Inc.
label: Description
content: This example came from the National Bureau of Standards. The inscription on a metal tag reads “A. Beckman Instrument Patents Issued and Pending Serial No. 5956 Model G Manufactured in U.S.A. by National Technical Laboratories – South Pasadena, Calif.” The Model G was introduced in 1937.
label: Location
content: Currently not on view
setName: label: See more items in
content: Medicine and Science: Chemistry
creditLine: label: Credit Line
content: Transfer from Excess Property, National Bureau of Standards
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: CH.326627
label: catalog number
content: 326627
label: accession number
content: 261654
objectType: label: Object Name
content: pH Meter
physicalDescription: label: Measurements
content: battery 3: 2 3/4 in x 4 in x 7/8 in; 6.985 cm x 10.16 cm x 2.2225 cm
label: Measurements
content: box: 28 cm x 28.5 cm x 21.5 cm; 11 in x 11 1/4 in x 8 7/16 in
label: Measurements
content: battery 1: 4 in x 2 5/8 in x 2 5/8 in; 10.16 cm x 6.6675 cm x 6.6675 cm
label: Measurements
content: overall in box: 11 1/2 in x 11 1/4 in x 8 1/4 in; 29.21 cm x 28.575 cm x 20.955 cm