Abstract: In order to solve the problem of the value transfer of tritium-in-air monitors in China,tritium activity concentration standard device was built up and the performance of the standard device was tested in laboratory. Testing results show that the device has a repeatability of 0.97%, a stability of 1.1%, activity concentration ranges between 5.0×10⁴ Bq·m^-3 to 2.0×10⁸ Bq·m^-3, and the relative extended uncertainty of 4.6%-5.0% (k=2) was achieved. This tritium activity concentration standard device has been authorized as social public measurement standard, which could be used for value transferring of tritium-in-air monitors in China.

Key words: tritium, activity concentration, tritium-in-air monitor, standard device, value transfer