Three terminal voltage measurements are made between Tip to Ring, Tip to Ground, and Ring to Ground. In the AC mode the technician can chose between Vac readings, or db for noise.
The DC voltmeter can measure and display changes in TR, TG, and RG in less than 2 seconds. This high speed allows the technician to rapidly test frame or cross connects to locate vacant pairs.
Noise measurements are made between TR and Ground. The display can be Vac (Vrms) or in dB (add 90 to obtain dbrn).
Note: -70db = 20dbrn.