1. (a) A licensee shall calibrate the survey instruments used to show compliance with He-P 4020 through He-P 4023 before first use, at intervals not to exceed 12 months, and following any repair that affects the calibration.

2. (b) To satisfy the requirements of He-P 4035.18(a), the licensee shall:

   1. (1) Calibrate all required scale readings up to 10 millisieverts (1000 mrem) per hour with a radiation source;
   2. (2) Calibrate 2 separated readings on each scale or decade that shall be used to show compliance; and
   3. (3) Clearly mark the date of calibration on the instrument.
3. (c) To satisfy the requirements of He-P 4035.18(b), the licensee shall use survey instruments if the difference between the indicated exposure rate and the calculated exposure rate is less than 20 percent.
4. (d) A licensee shall maintain a record of radiation survey instrument calibrations required by He-P 4035.18 for 3 years. The record shall include the model and serial number of the instrument, the date of the calibration, the results of the calibration, and the name of the individual who performed the calibration.

Source. (See Revision Note at part heading for He-P 4035) #6942, eff 2-1-99; ss by #8800, INTERIM, eff 2-1-07, EXPIRED: 7-31-07 New. #8959, eff 8-7-07; ss by #10897, INTERIM, eff 7-22-15, EXPIRES: 1-18-16; ss by #11011, eff 1-15-16; ss by #13048, eff 6-2-20; ss by #13473, eff 10-25-22; ss by #13817-A, eff 12-5-23