Briefly describe how to use the clamp ammeter
In addition to the current testing function and voltage drop testing method, there are still many functions of the multimeter that have not been fully utilized in maintenance, mainly as follows.
(1) Frequency testing
As long as the sensor can generate a frequency signal, it can be used for frequency testing with a multimeter. Such as intake pressure sensors and knock sensors. By fully utilizing the frequency testing function of the multimeter, the working status of the frequency signal sensor can be tested and the performance of the sensor can be judged.
(2) Test of duty cycle
The duty cycle is a percentage value of the working time of a signal compared to the total time. Using a multimeter to test the duty cycle of components such as the idle control valve that adopts the duty cycle control method can determine situations such as the idle control valve not acting, acting, and acting inaccurately.
(3) Measurement of closure angle
Measuring the closure angle can reveal the related causes of ignition, such as the distance between the distributor contacts and mechanical wear of the distributor. The method is as follows: ① Insert the black probe into the COM socket and the red probe into the corresponding socket of the closed angle. ② According to the measured number of engine cylinders, place the function switch on the desired "DWELL" range. ③ Ground the black probe or connect it to the negative terminal of the battery, and connect the red probe to the low-voltage terminal of the distributor or the negative terminal of the ignition coil Start the engine to read the closing angle.
(4) Special functions should be well utilized
Some car multimeters have unique functions, such as analog conversion modules (referred to as conversion modules), which can simulate sensor signals and drive actuators. If these functions are used properly, efficiency can be greatly improved.
Multimeters can also play many other roles in maintenance, and there is still much to be explored in practice. Only by continuously expanding and adopting new application methods in repair work can maintenance efficiency be improved.
