Take a sneak peek at the new NIST.gov and let us know what you think!
(Please note: some content may not be complete on the beta site.).

View the beta site
NIST logo
Bookmark and Share

Air-kerma Calibrations in Radiation Protection Level Cs-137 and Co-60 Gamma Ray Beams


The Dosimetry Group maintains and disseminates the national measurement standards for air-kerma (exposure) from 137Cs and 60Co gamma-ray beams and for absorbed dose to water from 60Co gamma-ray beams.


The national standard for air kerma is disseminated throughout the U.S. by way of a network of secondary calibration facilities that in turn calibrate radiation detection instruments such as ionization chambers, survey meters, electronic personal dosimeters (EPDs), thermoluminescent dosimeters (TLDs), portal monitors, isotope identifiers, etc. Such instruments are used by radiation workers and users in the field of radiation protection, emergency response, homeland security, medicine and industry. A large number of institutions benefit from the use of radiation detection instrumentation including the U.S. Navy, Army and Air Force, the U.S. Department of Energy (DOE), hospitals, universities, nuclear power plants, police departments, fire departments, etc. In addition to disseminating calibration measurements, proficiency tests are also provided by NIST to secondary calibration facilities of radiation protection level instrumentation. This ultimately ensures the safety of radiation instrument users and the public.

Cs-137 and Co-60 Air Kerma Calibration Instruments
Photographs by: Ronaldo Minniti

End Date:


Lead Organizational Unit:


Ronaldo Minniti