Which functions of the multimeter are underused
1. "Give up on choking" for some functions
Some maintenance personnel are often afraid to use a multimeter because they are worried about damaging the equipment during the test, the most obvious one is the current test. The current test method is not complicated, such as the starting current, the primary and secondary current of the ignition coil, and the current test of the fuel injector, many fault clues can be found as a basis for diagnosis, but technicians rarely use it in maintenance. It is understood that many repairmen are afraid to use the current test function because they are afraid of "burning the meter" or damaging the components under test due to misoperation of the test. In fact, many multimeters are designed with special circuit devices or mechanical protection devices in order to protect integrated circuits. For example, one more DY2201 multimeter adopts a mechanical protection device for the current measurement jack to prevent misuse. Only when current measurement is selected, the corresponding "mA" or "20A" jack will be opened. Otherwise, it will be blocked by the baffle, which can effectively avoid inserting the wrong test leads. Maintenance personnel can boldly use the current test function, but must operate in accordance with the use process.
2. Insufficient emphasis on errors in testing
Any instrument will have errors in the measurement, but the errors should be minimized in the measurement to avoid operating errors to ensure the accuracy of the measurement results. The large errors that often occur in the use of multimeters are sometimes caused by instruments, and sometimes caused by some human factors. The following two aspects need to attract the attention of maintenance personnel: ①Because the accuracy and resolution of the multimeter are not enough, if the judgment is only based on estimation, it will often lead to human error. ②Due to the different test methods of various multimeters, the multimeters will have their own instrument errors in different signal tests. Therefore, when using multimeters, maintenance personnel should try to use instruments with high precision levels, and at the same time strictly follow the operating procedures. reduce the error.
3. The current test function has not been paid attention to
For a long time, the current test function has been neglected in maintenance. With the emergence of more and more new technical equipment on the car, sometimes it is impossible to carry out effective diagnosis without current test. For some leakage situations that are difficult to judge, such as: ①The battery plates are short-circuited or oxidized and fall off, resulting in self-discharge and power loss. ②Electronic components are grounded to cause leakage, such as the insulation layer of a certain line in the circuit is aging or falling off, resulting in contact with other metal parts. In these cases, the multimeter's current test function can come in handy.
