TM 11-6625-298-14
The guard circuit prevents leakage current along
the surface of the instrument case between the
The guard circuit as shown in figure 5-6 increases
ground terminal and the line terminal from af-
the accuracy of the instrument by preventing
fecting the meter readings. Leakage current to the
leakage when making measurements over 100
line terminal is picked up by the guard ring and
megohms. The guard circuit consists of a metal
led directly to the generator without going through
ring around the line terminal and metal plates on
resistor R1 and the meter coils.
which resistor R1, R2, and R3 are mounted. A
brass tube connects the ring and plates together.
