Introduction to the connection between the ammeter and the circuit under test and the inspection before measurement
Inspection before measurement
Before measurement, check whether the pointer of the ammeter is aligned with the "0" scale line. If it is not aligned, adjust the "zero adjuster" to make the pointer return to zero.
The connection between the ammeter and the circuit under test
(1) When measuring, the ammeter should be connected in series to the low potential side of the circuit under test.
(2) When measuring DC, you need to pay attention to the symbol of the ammeter terminal button. For a single-quantity limit ammeter, the measured current should flow into the ammeter from the terminal button marked with "+", and flow out of the ammeter from the terminal button marked with "-"; For multi-quantity ammeters, the one marked with "*" is the common terminal button. If the other terminal buttons are marked with "+" symbols, the measured current should flow in from the "+" terminal button and flow out from the "*" terminal button; if other The terminal button is marked with a "-" symbol, and the connection is just the opposite of the above situation.
correct reading
When reading, the pointer should be stable before reading, and keep the line of sight perpendicular to the dial as soon as possible. If the dial has a mirror, the pointer and the shadow of the pointer in the mirror should be coincident to reduce the error.
