Haefely Technology 2291

The 2291 and 2292 high current resistance meters are special designed for high performance measurement of high inductance, low value resistances such as transformer windings, motors, breakers, switchgear etc. Unlike normal resistance meters these instruments have a built-in high-speed discharge circuits for safe discharge of the stored energy in a measured inductance.
Operation is fully automatic and the powerful DC test current produces high accuracy and rapid saturation of the test object. So virtually all sizes of transformer can be measured.
Covered measuring range 1 uOhm - 20 kOhm, measuring current up to 33A (2291) respectively 50A (2292).

Haefely Technology 2291 datasheet & specifications