The usage method and precautions of clamp ammeters
Types and structures of clamp ammeters
Ammeters can be divided into two forms: pointer ammeters and digital ammeters. A pointer ammeter generally consists of a dial, a needle, a dial, a zero adjustment device, etc; The digital ammeter directly displays the current value through the display screen. Whether it is a pointer type or a digital ammeter, the basic principle is to measure the strength of the current by applying a magnetic field generated by the current to the pointer or induced current on the measuring coil to generate a corresponding voltage.
Usage of clamp ammeter
1. Preparation work
Before using an ammeter, some preparation work needs to be done first.
(1) Choose a suitable ammeter: Choose a suitable ammeter based on the current range that needs to be measured, ensuring that the range of the ammeter can cover the required measurement range.
(2) Check circuit safety: Ensure that the circuit to be measured is in a safe state and free from damage or leakage. At the same time, the circuit should be kept energized to maintain normal measurement.
(3) Calibration of ammeter: Before using the ammeter, it is best to calibrate it to ensure the accuracy of the measurement results.
2. Connect the circuit
To connect an ammeter, it needs to be installed on a branch line in the circuit to measure the current passing through that branch line. When connecting an ammeter, pay attention to the following points:
(1) Circuit disconnection: Before connecting the ammeter to the circuit, the circuit should be disconnected.
(2) Choose the appropriate connection method: The ammeter can be connected in series or parallel to the circuit, and the selection of the appropriate connection method can be determined according to the specific situation.
(3) Maintain good contact: Use a pin or crocodile clip to firmly connect the positive and negative terminals of the ammeter to the circuit and maintain good contact.
3. Zero adjustment and range adjustment
After connecting the circuit, it is necessary to perform zero adjustment and range adjustment operations.
(1) Zero adjustment: Adjust the ammeter to the zero position, that is, when there is no current flowing, the pointer indicates at the zero position of the scale. Zero adjustment is to eliminate errors and improve measurement accuracy.
(2) Adjust the range: Adjust the range of the ammeter according to the current range that needs to be measured. A small range may cause excessive pointer deflection, while a large range may reduce the sensitivity of the ammeter.
