The transformer turns-ratio is determined by precisely measuring the voltages across the unloaded transformer windings. The Vanguard ATRT-01B Battery Powered Single Phase TTR measures circuitry, and self-adjusts before each measurement to ensure turns-ratio accuracy.

Vanguard ATRT-01B Battery Powered Single Phase TTR features:

• Single Phase TTR 
• Measure turns-ratios from 0.8 to 15,000 
• Calculate turn-ratio in percentage 
• Measure and displays winding excitation current and polarity 
• Stand alone or computer controlled 
• ATRT-01 – line powered unit / ATRT-01B battery powered unit