(1) The registrant shall maintain sufficient calibrated and operable radiation survey instruments to make physical radiation surveys as required by this part and chapter 246-221 WAC. Instrumentation required by this section shall have a range such that two milliroentgens per hour through one roentgen per hour can be measured.

(2) Each radiation survey instrument shall be calibrated:

(a) At energies appropriate for use and at intervals not to exceed three months and after each instrument servicing;

(b) Such that accuracy within ± twenty percent traceable to a national standard can be demonstrated; and

(c) At two or more widely separated points, other than zero, on each scale.

(3) Records of these calibrations shall be maintained for three years after the most recent calibration date.

(4) The requirements of this section do not apply to registrants using only radiation machines in enclosed radiographic systems.