Megger manufactures transformer ohmmeter which is a transformer winding resistance and tap-changer test set. It is a lightweight, field portable unit which is safely and accurately measures the dc winding resistance of all types of transformers and rotating machines. A built-in circuitry safely discharges the specimen when the test is completed. The transformer ohmmeter is extremely useful when testing the operation of on-load tap-changers. This instrument can be used to check the make-before-break operation of on-load tap-changers and also to measure the contact resistance of each tap position. The salient features of transformer ohmmeter:
