Abstract: A precision op amp test circuit employs latching relays, the contacts of which are latched open or closed as necessary to make test measurements. The relays' metal contacts ensure low resistance conductive paths, and because the coil of a latching relay need be energized only briefly to latch the contacts, the heating duty cycle of the coils can be kept low to substantially eliminate the accuracy-degrading thermal E.M.F. generated by the heat from the energized coil of a conventional relay. The test circuit is advantageously used for testing both VOS and IB for high precision, low-VOS op amps.