Records of periodic spot-checks for teletherapy units.

§ 35.2642 Records of periodic spot-checks for teletherapy units. (a) A licensee shall retain a record of each periodic spot-check for teletherapy units required by § 35.642 for 3 years. (b) The record must include— (1) The date of the spot-check; (2) The manufacturer's name, model number, and serial number of the teletherapy unit, source and instrument used to measure the output of the teletherapy unit; (3) An assessment of timer linearity and constancy; (4) The calculated on-off error; (5) A determination of the coincidence of the radiation field and the field indicated by the light beam localizing device; (6) The determined accuracy of each distance measuring and localization device; (7) The difference between the anticipated output and the measured output; (8) Notations indicating the operability of each entrance door electrical interlock, each electrical or mechanical stop, each source exposure indicator light, and the viewing and intercom system and doors; and (9) The name of the individual who performed the periodic spot-check and the signature of the authorized medical physicist who reviewed the record of the spot-check. (c) A licensee shall retain a copy of the procedures required by § 35.642(b) until the licensee no longer possesses the teletherapy unit.