[Code of Federal Regulations] [Title 10, Volume 1] [Revised as of January 1, 2001] From the U.S. Government Printing Office via GPO Access [CITE: 10CFR35.51] [Page 563-564] TITLE 10--ENERGY CHAPTER I--NUCLEAR REGULATORY COMMISSION PART 35--MEDICAL USE OF BYPRODUCT MATERIAL--Table of Contents Subpart C--General Technical Requirements Sec. 35.51 Calibration and check of survey instruments. (a) A licensee shall calibrate the survey instruments used to show compliance with this part before first use, annually, and following repair. The licensee shall: (1) Calibrate all scales with readings up to 1000 millirem per hour with a radiation source; [[Page 564]] (2) Calibrate two separated readings on each scale that must be calibrated; and (3) Conspicuously note on the instrument the apparent exposure rate from a dedicated check source as determined at the time of calibration, and the date of calibration. (b) When calibrating a survey instrument, the licensee shall consider a point as calibrated if the indicated exposure rate differs from the calculated exposure rate by not more than 20 percent, and shall conspicuously attach a correction chart or graph to the instrument. (c) A licensee shall check each survey instrument for proper operation with the dedicated check source each day of use. A licensee is not required to keep records of these checks. (d) A licensee shall retain a record of each survey instrument calibration for three years. The record must include: (1) A description of the calibration procedure; and (2) The date of the calibration, a description of the source used and the certified exposure rates from the source, and the rates indicated by the instrument being calibrated, the correction factors deduced from the calibration data, and the signature of the individual who performed the calibration. [51 FR 36951, Oct. 16, 1986, as amended at 53 FR 19247, May 27, 1988]