On 4th September, 2012, PONOVO successfully won the bidder of partial discharge relay testing system of Beijing Electric Power Company. The tester SAMOS was applied in the project. After Pocket AE-Power, SAMOS is the second ultrasound discharge test system cooperated by PONOVO and Physical Acoustics Corporation. Compared with portable dual-channel PAP linear polarization, multi-channel SAMOS has the function of partial discharge three-dimension polarization which is suitable for transformer and resistance, etc partial discharge detection and polarization of large electric equipments. In previous competition held by EPRI, it performs excellently.