Minn. R. agency 144, ch. 4731, INDUSTRIAL RADIOGRAPHY, pt. 4731.4060

Current through Register Vol. 49, No. 29, 2025

Part 4731.4060 - RADIATION SURVEY INSTRUMENTS

Subpart 1.Required instruments.

A licensee must keep sufficient calibrated and operable radiation survey instruments at each location where radioactive material is present to make the radiation surveys required under parts 4731.2000 to 4731.2950 and 4731.4000 to 4731.4360. Instrumentation required under this part must be capable of measuring a range from two millirems (0.02 mSv) per hour through one rem (0.01 Sv) per hour.

Subp. 2.Calibration.

A licensee must have each radiation survey instrument required under subpart 1 calibrated:

A. at intervals not to exceed six months and after instrument servicing, except for battery changes;

B. for linear scale instruments, at two points located approximately one-third and two-thirds of full-scale on each scale; for logarithmic scale instruments, at midrange of each decade and at two points of at least one decade; and for digital instruments, at three points between two and 1,000 millirems (0.02 and 10 mSv) per hour; and

C. so that an accuracy within plus or minus 20 percent of the calibration source can be demonstrated at each point checked.

Subp. 3.Record keeping.

A licensee must maintain records of the instrument calibrations that are required under this part and must retain each record for three years after it is made.

Minn. R. agency 144, ch. 4731, INDUSTRIAL RADIOGRAPHY, pt. 4731.4060

29 SR 755

Statutory Authority: MS s 144.1202; 144.1203