Universal measuring bridge `` UM-3 '' (E2-12).
Instruments for adjusting and controlling the PTA.The universal measuring bridge "UM-3" has been producing the Velikie Luki radio plant since the 1st quarter of 1957. Since 1963, the E12-2 universal measuring bridge has been produced by the Leningrad Izmeritel plant. Both devices are similar. The universal measuring bridge '' UM-3 '' subsequently '' E12-2 '' is designed to measure resistances at direct current, capacities, loss tangents, inductances and Q-factors of coils at frequencies of 100 and 100 Hz. When using an external generator, coil measurements can be made at other frequencies. Read more about the device below.