UT15C voltage tester circuit continuity, phase shift Uni-TUNI T universal voltage tester meter UT15C The multifunctional and durable meter allows you to measure voltages from 12 to 690V AC DC. The appropriate range is selected automatically. The measurement result is presented by the lighting of a diode at the corresponding voltage and displayed on the LCD screen. Conductivity is indicated optically by the illumination of the diode and acoustically by an audible signal. The device also has LED illumination,