Current measurement is different from other digital multimeter measurement.
If using digital multimeter for current measurements alone, need the multimeter and series circuit under test.
That means the circuit disconnect, form a complete circuit and digital multimeter test line.
In this way, all the circuit current through the circuit of digital multimeter.
Current is measured with a digital multimeter an indirect method is to use the current probe.
Will be clipped on the outside of the conductor, and thus do not need to disconnect series circuit and digital multimeter.
Disconnect the circuit of power supply.
Disconnect the circuit or the desoldering, resulting in a pluggable multimeter probe position.
According to the needs, select A ~ (
Or A (
Put the black test probe COM input jack.
According to the expected reading values, the red test probe inserted into the amp or ma input jack.
Connect the probe tip in the disconnected points at both ends, so that all the current flows through the digital multimeter (
To switch the circuit on.
See the readings, be sure to pay attention to the unit of measure.
Note: if the reverse when dc measurements will test line, then the screen will show '?
Dc and ac current is a common mistake is still in the test line current input jacks, trying to make voltage measurements.
This will cause for low value resistor in digital multimeter (
Called a shunt)
And on both ends of the power supply direct short circuit.
If a large current will flow through digital multimeter, inadequate protection, the digital multimeter and circuit are larger damage, may also hurt the operator.
If involved in industrial high pressure circuit (
240 v or higher)
, can produce high fault current.
Therefore, digital multimeter should have current input fuse protection, the protection ability should be high enough for the circuit under test.
In the current input without a multimeter cannot be used to measure high energy circuit fuse protection (>
For digital multimeter with fuse, fuse breaking capacity should be sufficient to remove high energy failure.
Multimeter fuse voltage rating should be greater than expected the highest voltage measurement.
For example, on both ends of the multimeter pick in the 480 v circuit, a 20 a / 250 v fuse multimeter may not be able to remove the faults.
In order to remove the 480 v circuit fault, need to use a 20 a / 600 v fuse.