Cobalt 60 secondary gamma-ray standard, 1 rd (10E6 dps)
date: label: date made
content: 1948
name: label: maker
content: National Bureau of Standards
notes: label: Description
content: Background on secondary gamma-ray standards, Object IDs 1994.0125.55, .56, .57, & .58
label: Description
content: Instruments used for radiation detection, measurements, or surveys need to be calibrated periodically. A radioactive source (not necessarily calibrated) is used to confirm the satisfactory operation of an instrument. A standard source is a radiation source exhibiting a disintegration (e.g., disintegrations per second or dps), emission or exposure rate certified by or traceable to the U.S. National Institute of Standards and Technology (NIST), formerly the National Bureau of Standards (NBS). NIST maintains the primary radiation sources, and makes available and/or certifies secondary sources for instrument calibration. For details on survey instrument calibration, see:
label: Description
content: http://www.rso.utah.edu/policies/rpr/52instrucare/52instrucare.pdf
label: Description
content: Detailed description of Cobalt 60 secondary gamma-ray standard, 1 rd, Object 1994.0125.55
label: Description
content: Glass ampoule, approximately 3” long, 5/8” in diam., held by cotton wool in test-tube shaped transparent container capped by a shiny steel screw-cap 5 3/4” long, 7/8” diam. About two-thirds of the ampoule volume contains a slightly pinkish-tinged liquid. A small paper label is glued on the ampoule with typed legend: Co[E]60 / “1 rd”.
label: Description
content: Received with NBS certificate, dated 1948 Jan. 30, stating that the ampoule contains 1.59 rutherfords (rd) per milliliter, and a subsequent correction that it contains 1.59 rd, total. (Herbert Clark’s letter 1994 May 4, identifies the rutherford as unit of radioactivity, 1 rd = 10E6 dps, introduced in 1946, but short-lived. The new unit is the Becquerel (bq), where 1 bq = 1 dps). The plastic container for the ampoule has a small adhesive label with the following printed words: “Caution Radioactive Material”.
label: Location
content: Currently not on view
topic: label: Subject
content: Science & Scientific Instruments
setName: label: See more items in
content: Medicine and Science: Modern Physics
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content: Science & Mathematics
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content: Modern Physics
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content: Measuring & Mapping
creditLine: label: Credit Line
content: Rensselaer Polytechnic Institute. Department of Chemistry
dataSource: label: Data Source
content: National Museum of American History
identifier: label: ID Number
content: 1994.0125.55
label: accession number
content: 1994.0125
label: catalog number
content: 1994.0125.55
objectType: label: Object Name
content: gamma-ray standard, secondary, Co60
physicalDescription: label: Physical Description
content: liquid with cobalt 60 (overall material)
label: Physical Description
content: plastic (overall material)
label: Physical Description
content: cotton (overall material)
label: Physical Description
content: steel (overall material)
label: Physical Description
content: paper (overall material)
label: Physical Description
content: glass (overall material)
label: Measurements
content: overall (transparent, capped plastic container): 5 3/4 in x 7/8 in; 14.605 cm x 2.2225 cm
label: Measurements
content: glass ampoule: 3 in x 5/8 in; 7.62 cm x 1.5875 cm