clamp ammeter circuit

When using an ammeter to measure the current in a circuit, you need to disconnect it and connect it in series in the circuit before you can measure it. The clamp ammeter
can directly measure the current in the line without disconnecting the circuit
. Figure 5-1 shows the appearance and circuit of a clamp ammeter .
    (1) Structural Principle of Clamp Ammeter The main
component of clamp current meter is a through-core current transformer. When measuring,
the magnet of the clamp ammeter is placed on the wire under test to form a 1-turn primary
coil. According to the principle of electromagnetic induction, an induced
current will be generated in the secondary coil, and the ammeter pointer connected to the secondary wire network Deflection occurs
, indicating the value of the current in the line.
    (2) How to use the clamp ammeter
    1> Zero adjustment position: Before measuring the current, check whether the meter needle points
to zero. If it does not point to zero, use a small screwdriver to adjust
the zero adjustment bolt on the meter head so that the meter needle points to zero. bit to improve reading accuracy
.
    2) Select the gear: When using the clamp ammeter, you must choose the gear correctly
. Before measuring, you should estimate the size of the current to be measured and select the appropriate range.
Do not use the small range to measure large currents.
    When measuring, turn the range switch to the appropriate position. Hand-held
Bakelite handle. Use your index finger to hook the iron core switch to open the iron core and introduce the wire under test from the gap in the iron core to the center of the iron core. Then, relax the index finger that
tightly hooks the iron core switch , the iron core will automatically close, and the current of the measured wire will generate alternating magnetic lines in the iron core, and there will be an induced current on the meter, which can
be read directly.