Ambient dose equiovalent or ambient dose equivalent
rate for neutron radiation is measured with portable direct-reading instruments. For numerous applications (e.g. for checking permissible boundary values for the dose rate at a CASTOR transport container), it is prescribed that calibrated measuring instruments be used. It thus is ensured that the values measured are traceable to a primary standard.
Every year the PTB carries out up to 20 calibrations of area neutron monitors using its radionuclide neutron sources. The calibration, performed on the basis of the international standards ISO 8529 and IEC 1005, covers the determination of the calibration factor, of the linearity of the response and of the photon sensitivity. The calibration factor of an area monitor must be independent of the conditions prevailing in the measurement room, i.e. it is to be determined for a source spectrum which would exist in vacuum. This "direct" radiation is, however, always accompanied by a stray radiation component whose influence must be eliminated by a suitable test method (e.g. shadow object method or distance variation method).
The measurement results are compiled in a calibration certificate, and the measurand usually is the ambient dose equivalent H*(10). Calibrations regarding the neutron flux density are also possible. These services are provided in accordance with the quality system of the PTB. The charges are fixed in accordance with the Regulations governing charges for services rendered by the PTB in their version at present applicable.
Here you find dedtails of the calibration capabilities offered by our radionuclide neutron sources.
Contact
Dr. Andreas Zimbal
Phone: +49 (0) 531-592-6530
e-mail: Andreas.Zimbal@ptb.de
