The use process of millivolt meter

(1) The millivoltmeter should be placed vertically, not horizontally. Before powering on, the mechanical zero screw on the meter head should be adjusted so that the meter needle indicates zero (Note: the mechanical zero does not need to be adjusted frequently).

(2) Select the voltage range according to the size of the measured signal. If the size of the measured signal is unknown, select the largest range first and then gradually reduce it to the appropriate range.

(3) Turn on the power, wait for the needle to stabilize, short-circuit the input line, and adjust the zero adjustment knob. When the needle points to zero, you can start measuring.

(4) When measuring, first connect the ground wire (shielded wire) of the input line to the common point of the circuit being measured, and then connect the non-ground end of the input line to the point on the side being measured. After the measurement is completed, remove the non-ground end first and then disconnect the ground wire.

(5) When this meter is used as a level meter, the actual level value is the algebraic sum of the dB number indicated by the meter needle and the decibel number indicated by the range switch.