Radium secondary gamma-ray standard, 0.100x10E-6 gm

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 Radium secondary gamma-ray standard, 0.100x10E-6 gm, Object 1994.0125.58
(One of the accompanying] photographs provided by donor, Prof. Herbert Clark, Rensselaer Polytechnic Institute.)
Flat-bottomed glass ampoule, approximately 3 1/8” long, 5/8” diam., held by cotton wool in a test-tube shaped container capped by a shiny steel screw-cap, 5 ¾” long, 7/8” diam. The ampoule is more than two-thirds full of colorless liquid. The ampoule bears a legend printed on the glass: “0.1 Micro gms. / Radium”. The top of the containing tube bears an adhesive label with the following words printed: “CAUTION / [symbol] / RADIOACTIVE / MATERIAL”
Currently not on view
Object Name
gamma-ray standard, secondary, Ra
date made
National Bureau of Standards
Physical Description
plastic (overall material)
cotton (overall material)
steel (overall material)
paper (overall material)
liquid with radium (overall material)
glass (overall material)
overall (transparent, capped plastic container): 5 3/4 in x 7/8 in; 14.605 cm x 2.2225 cm
glass ampoule: 3 1/8 in x 5/8 in; 7.9375 cm x 1.5875 cm
ID Number
accession number
catalog number
Science & Scientific Instruments
See more items in
Medicine and Science: Modern Physics
Science & Mathematics
Measuring & Mapping
Modern Physics
Data Source
National Museum of American History, Kenneth E. Behring Center
Credit Line
Rensselaer Polytechnic Institute. Department of Chemistry
Additional Media

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