Intercomparison of environmental dosimeters between China and Japan

Objective: For assuring accuracy and reliability of the monitoring results provided by thermoluminescence dosimetry laboratories ,an intercomparison with JCAC was performed for several years so as to inspect the veracity and stability of measurement systems of thermoluminescence dosimetry. Methods: The method adopted was sending TLD by post and setting up two different monitoring places and one control place for every time of intercomparison. One dosimeter containing six to ten detectors was placed in each measurement site. The dosimeters were measured by both laboratories after taking back. Results: The results of intercomparison for three successive times showed that the consistency rates of these environmental dosimeters were all less than seven percent, i.e., within the permissible error range. Conclusion: The measurement systems of thermoluminescence dosimetry and monitoring methods adopted by these thermoluminescence dosimetry laboratories accord with the requirement of both national and international standards. The consistency has been kept for three times of comparisons in six years. The monitoring methods, the calibration reproducibility of measurement equipment, the selection of TLD and the processing methods of comparison results adopted in intercomparison of environmental dosimeters with JCAC all reach the international level. (authors)