NRSB Policy on Instrument Calibration

 1. By “instrument”, NRSB specifically includes all continuous radon monitors (method CR), and all continuous radon decay product (RDP) monitors (method CW).

2. An instrument “calibration” comprises exposure of the instrument to one or more known radon (or RDP) concentrations under known environmental conditions in an accredited chamber facility, followed by the alignment and adjustment of the instrument according to the manufacturer’s instructions and as appropriate to bring its accuracy to within the manufacturer’s predetermined tolerances, as well as the issuance of a “certificate of calibration”.

3. The exposure of an instrument to a known radon (or RDP) concentration does NOT in itself constitute an instrument “calibration”, although such activity may be performed by an accredited chamber as a necessary part of an instrument calibration.  

4. An accredited radon chamber may adjust an instrument as a required part of an instrument calibration only with prior authorization to do so by the instrument manufacturer.

5. The manufacturer’s authorization of an accredited chamber to perform instrument calibration must be expressed in writing by the manufacturer, with a copy of the authorization letter sent to NRSB before the chamber may advertise the availability of an instrument calibration service or engage in the calibration of an instrument. The authorization letter must list all instrument models which the manufacturer authorizes the chamber to calibrate. If the manufacturer revokes its authorization of an accredited chamber to perform calibration of one or more instrument models, the chamber must immediately discontinue such activities and inform NRSB of the revocation within 30 calendar days.

6. The NRSB maintains a list of accredited chambers and the instruments which each chamber is manufacturer-authorized to perform calibration. The full list of instrument calibration authorizations will be available from the NRSB web site (www.nrsb.org).

7. A chamber that advertises the availability of an instrument calibration service or engages in such service without the manufacture’s authorization is not compliant with this policy and is subject to either non-renewal or immediate revocation of its accreditation by NRSB.

8. In unusual circumstances, such as an instrument manufacturer’s demise, a chamber may appeal to NRSB for a partial waiver or a temporary waiver of this policy; NRSB will handle such appeals on a case-by-case basis.