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We have developed a large area multi-wire proportional counter(MWPC) as a standard for the measurement of alpha and beta surface emission rate at the Shanghai Institute of Measurement and Testing Technology(SIMT). To shorten the preparation time for chamber gas refilling, a self-designed gas control unit was adopted.Various characteristics of the system have been studied. The uncertainties were analysed. Three certified alpha plane sources(Am-241) and six certified beta plane sources(Tl-204 and Sr-90/Y-90) were measured by this system. The results show excellent agreement with the surface emission rate reported by the National Institute of Measuring,China(NIM) that E n values of all measured sources are within ±1.
We have developed a large area multi-wire proportional counter (MWPC) as a standard for the measurement of alpha and beta surface emission rate at the Shanghai Institute of Measurement and Testing Technology (SIMT). To shorten the preparation time for chamber gas refilling, The uncertainties were analysed. Three certified alpha plane sources (Am-241) and six certified beta plane sources (Tl-204 and Sr-90 / Y -90) were measured by this system. The results show excellent agreement with the surface emission rate reported by the National Institute of Measuring, China (NIM) that E n values of all measured sources are within ± 1.