The model BPS TE spherical chambers have been constructed. The basic performances of the chambers have been determined. The chambers are three terminal devices with gas inlet and outlet During operating the chamber at 250 V and 500 V, the saturation correction factors are 1.003 and 1.0007, respectively. The relative change of the response for the chamber is less than 0.5 per cent when the angles of the incident radiation are changed in the range of 0°~120° for the ,60,Co gamma rays. The stem effect and the energy response of the chamber have been studied. The results of measurement show that the variation of the composition of TE-gas will cause noticeable error