The Megger TTR100 is an automatic handheld, battery operated transformer turns ratio test set used to measure the turns ratio, excitation current, phase displacement, dc resistance and polarity of windings in single- and three-phase distribution transformers (tested phase by phase), potential & current transformers, and tapped transformers. Deviations in the mentioned measurements will quickly indicate problems in transformer windings or in the magnetic core circuits. The unique design of the TTR100 allows the user to operate the test set while holding it in one hand. No other transformer test set offers this capability. It effectively eliminates the user from having the kneel or bend down.