Tham khảo tài liệu 'radiation protection manual episode 4', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | EM 385-1-80 30 May 97 is done by attaching a Dewar flask containing liquid nitrogen to the detector. HPGe systems are being made that are field portable using small Dewar flasks and laptop computers and can provide laboratory quality analysis in the field. g. Energy proportional detectors such as scintillation detectors semiconductor diode detectors and HPGe detectors are often coupled with a multichannel analyzer MCA to allow for determination of the energy of the radiation detected and through reference to determine the radioisotope that emitted the radiation and the quantity of that isotope in the sample measured. Most modern MCAs are used in conjunction with computers which process the information contain the library of radionuclides referenced by energy of radiation and display software for digital and graphic output. h. Instrument Calibration. 1 Radiation survey meters are calibrated with a radioactive source and an electronic pulser. When an electronic calibration is performed the instrument is checked for response to a radioactive source. In most situations survey meters must be calibrated at least annually and after servicing. Battery changes are not considered servicing . 2 Survey meters will be function tested with a check source or other dedicated source before each use. If the survey meter is not responding properly it may not be used for surveys until it is repaired. There is no need to keep a record of the function checks but a record must be kept of the discovery of the improper response and the service of the meter to correct the problem as well as of the recalibration of the meter. I. Quality Control. Quality control of instrumentation is essential in a radiation protection program. All instruments used for monitoring safety and health should be subjected to a quality control QC program. Two tracking trending methods are commonly used in instrument QC. The general principle is applicable to both field and lab instruments. The two methods are .
