What is a Clamp Ammeter?
Clamp ammeter, clamp ammeter is a device for measuring electrical current (AC or DC) without disconnecting the cable.
In the traditional method, using a multimeter or ohmmeter, the part of the cable from which the current is considered must be separated, and the multimeter is placed in series in the circuit, and then the amount of current in terms of microamperes, milliamperes and maximum amps up to 20A is displayed. .
But in this method, without the need to cut the cable, the clamp or rake of the ammeter is thrown around the cable and the current is observed.
The difference is that the current measuring range in this model of clamps is in the range of 100A, 1000A and even 3000A (will be explained below).
How to measure current in pliers ammeters
AC current measurement
How to calculate current in AC clamps is based on the rules of current transformer (CT).
The current transformer uses a magnetic flux generated by the current passing through the conductor to produce a current that is proportional to the current passing through the conductor or the corresponding cable.
The secondary current is calculated by a measuring circuit connected to a transformer winding;
The current under test is equal to the product of the secondary current divided by the number of turns of the transformer winding.
AC / DC current measurement
To measure DC current, a Hall effect sensor is used to detect current;
Because it is not possible to induce electromagnetism in AC clamps (previous title).
The Hall effect sensor is placed in the middle of the transformer outlet.
When the magnetic flux current is proportional to the initial AC or DC current, the Hall sensor detects the magnetic flux and its output is voltage.
Hall effect sensor
This sensor is a semiconductor.
When the primary current is applied to the input terminal, a voltage proportional to the initial current and the magnetic field generated at the output terminal is generated.