Abstract: Aiming at a large area portable surface contamination survey meter used in measuring α,β radiation,and ensuring the performance of measurement of the meter,the main performance of self-made instrument was measured based on JJG 478—2016 and GB/T 5202—2008 standards,including the uniformity of detector,surface emission rate response,minimum detectable limit,response time and temperature stability.The results show that the surface emission rate response of alpha for ²⁴¹Am is around 30.4%,of beta for ⁹⁰Sr-⁹⁰Y is around 48.1%,and of beta for ³⁶Cl is around 45.5%.The minimum detectable limit of alpha for ²⁴¹Am is 0.15 Bq/cm²,of beta for ⁹⁰Sr-⁹⁰Y is 0.07 Bq/cm²,and of beta for ³⁶Cl is 0.09 Bq/cm².The response time is less than 4 s.The instrument can operate normally in the temperature range of -10 ℃ to 40 ℃.These results are superior to the requirements of related standards and achieve the purpose of preventing the spread of radiation contamination to ensure the safety of field staff.

Key words: large area portable surface contamination survey meter, surface emission rate response, uniformity of detector