Abstract: In order to explore the influence of different influencing factors on the measurement efficiency of beta surface contamination, this paper mainly uses CoMo170 surface contamination monitor to measure the ⁶⁰Co plane source, the ²⁰⁴Tl plane source and the ⁹⁰Sr-⁹⁰Y plane source, and studies the influence of energy response, detection window response uniformity, measurement spacing, absorption effect, gamma ray interference and back scattering on the surface activity response, and the measurement uncertainty is evaluated. Through experimental research, the influence on the accuracy of the measurement results is obtained. Among them, the most influential factors are energy response and gamma ray interference. The final uncertainty evaluation result of the experimental measurement shows that its relative synthetic standard uncertainty is approximately equal to 46.71%.

Key words: beta surface contamination, surface activity response, influencing factors, measurement uncertainty