How to prevent the pointer of the multimeter from being bent and the head of the meter from being burned
Regarding the use of the multimeter, the bending of the pointer of the multimeter will affect the measurement results. If it is not used properly, the head of the multimeter will be burned. How to prevent the occurrence of these two kinds of accidents, let's understand together.
Preventive measures for multimeter pointer bending and meter burnout
When using the multimeter, if the operation is improper, the pointer will be bent, and if the situation is more serious, the meter head will be burned.
How to prevent the pointer of the multimeter from being bent and the head of the meter from being burned
To prevent such accidents, pay attention to the following when using the multimeter:
1) Before measuring, estimate the size to be measured, and turn the range switch to the appropriate range.
If you don't know the size to be measured, you can first set the range to the maximum range, and then slowly approach the appropriate range range.
Note that when measuring a large measured object with a small range, it is very likely to bend the pointer.
2) When measuring resistance, the circuit under test must be cut off from the power supply.
3) When testing high voltage or high current, it is forbidden to rotate the range switch. In order to avoid arcing on the contacts and damage to the switch.
4) When measuring electrolytic capacitors, first short-circuit and discharge them, and then measure.
5) When the multimeter is used incorrectly, the meter head may be burned.
Preventive measures: connect two silicon diodes in parallel at the positive and negative ends of the meter for protection (one in forward parallel and one in reverse parallel).
The conduction voltage of the silicon diode is generally greater than 0.5V, and the forward resistance of the silicon diode is large below 0.5V, which has little effect on the original internal resistance of the meter, and can be ignored.
When falsely detected, the increase in voltage will reduce the forward resistance of the silicon diode, and most of the current will be shunted by the diode to protect the meter.
The above are the relevant methods to prevent the pointer of the multimeter from being bent and the head of the meter from being burned. I hope it will be helpful to everyone.
