(a) A licensee authorized to use a remote afterloader unit for medical use shall perform full calibration measurements on each unit—

1. (1) Before the first medical use of the unit;

2. (2) Before medical use under the following conditions:

   1. (i) Following replacement of the source or following reinstallation of the unit in a new location outside the facility; and
   2. (ii) Following any repair of the unit that includes removal of the source or major repair of the components associated with the source exposure assembly; and
3. (3) At intervals not exceeding 1 quarter for high dose-rate, medium dose-rate, and pulsed dose-rate remote afterloader units with sources whose half-life exceeds 75 days; and
4. (4) At intervals not exceeding 1 year for low dose-rate remote afterloader units.

(b) To satisfy the requirement of paragraph (a) of this section, full calibration measurements must include, as applicable, determination of:

1. (1) The output within ±5 percent;
2. (2) Source positioning accuracy to within ±1 millimeter;
3. (3) Source retraction with backup battery upon power failure;
4. (4) Length of the source transfer tubes;
5. (5) Timer accuracy and linearity over the typical range of use;
6. (6) Length of the applicators; and
7. (7) Function of the source transfer tubes, applicators, and transfer tube-applicator interfaces.