Cobalt 60 secondary gamma-ray standard, 0.685x10E5 dps

Background on secondary gamma-ray standards, Object IDs 1994.0125.55, .56, .57, & .58
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:
Detailed description of Cobalt 60 secondary gamma-ray standard, 0.685x10E5 dps, Object 1994.0125.56
Flame sealed glass ampoule, 3” long, 5/8” diam., held by base and tip in a transparent cylindrical plastic container with black-painted aluminum screw cap, 3 ¾” long, 7/8” diam. About two-thirds of the ampoule volume contains a slightly pinkish-tinged liquid. A glued-on paper label, with a red border on 3 sides, handwritten in blue ink reads: “Nat. Bureau of Stds / Co[E]60 Gamma Ray Std / 0.685x10[E]5 dps on / Oct. 1, 1953”
Currently not on view
Object Name
gamma-ray standard, secondary, Co60
date made
National Bureau of Standards
Physical Description
plastic (overall material)
cotton (overall material)
aluminum (overall material)
paper (overall material)
liquid with cobalt 60 (overall material)
glass (overall material)
overall (transparent, capped plastic container): 3 3/4 in x 7/8 in; 9.525 cm x 2.2225 cm
glass ampoule: 3 in x 5/8 in; 7.62 cm x 1.5875 cm
ID Number
accession number
catalog number
Science & Mathematics
Science & Scientific Instruments
Measuring & Mapping
Modern Physics
See more items in
Medicine and Science: Modern Physics
Modern Physics
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Rensselaer Polytechnic Institute. Department of Chemistry

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