Field validation study of the MDA instant working level meter in a high gamma background mine environment.
Engleman-SD; Beaulieu-HJ; King-RH
Am Ind Hyg Assoc J 1984 Oct; 45(10):708-713
A field validation study of an instant working level meter (IWLM) in a high gamma radiation background mine environment was conducted. The MDA Model 811 IWLM beta detector was tested at an underground site in a Colorado uranium mine having a measured gamma background of 3 milliroentgens per hour. Side by side sampling was performed with the Model 811 and the Tsivoglou and Kusnetz measurement techniques. Fifty samples were obtained, 25 without any shielding and 25 with a 6 millimeter lead shield for the Model 811. Radiation levels measured by the Tsivoglou, unshielded Model 811, and Kusnetz procedures ranged from 0.27 to 1.17, 0.33 to 1.43, and 0.31 to 1.20 working levels (WL), respectively. Respective mean values were shielded Model 811, and Kusnetz techniques ranged from 0.24 to 1.10, values were 0.64, 0.84, and 0.60WL. The percentage error of the Model 811 relative to the Tsivoglou method was 38.3 percent for the unshielded meter and 31.3 percent for the shielded meter. The relationship between the Model 811 data and the Tsivoglou data was moderately linear, correlation coefficient 0.58. The correlation coefficient decreased to 0.43 when lead shielding was used. The authors conclude that data obtained with the Model 811 IWLM does not correlate satisfactorily with Tsivoglou data. Since the 811 generally gives higher WL values, its reading should be considered conservative. Using lead shielding is not recommended as it does not improve the correlation with the Tsivoglou method and its weight reduces portability.
NIOSH-Publication; NIOSH-Grant; Mining-industry; Radiation-measurement; Radiation-exposure; Gamma-radiation; Industrial-hygiene; Equipment-reliability; Radiation-detectors
Microbiology Colorado State University Department of Microbiology Fort Collins, Colo 80523
American Industrial Hygiene Association Journal
Colorado State University, Fort Collins, Colorado