Basic functions and characteristics of multimeter
In the maintenance of automotive electronic control system failures, in addition to the need to often detect voltage, resistance, capacitance, inductance, semiconductor components and current, etc. The parameters such as engine speed, closing angle, frequency, pressure, time, temperature and frequency (duty ratio) should also be detected. However, these parameters are often used in general digital multimeter detection effect is not good, some parameters can not be detected, it is necessary to use a special multimeter vehicle to detect.
First, the most basic automobile digital multimeter shape structure. Fig. 1 shows a schematic diagram of the configuration of the most basic digital multimeter of the automobile. The functional switches, sockets, etc., on the panel are described as indicated in fig. 1 .This kind of multimeter can realize the most basic function of automobile fault detection.
Second, the function characteristic of the most basic automobile digital multimeter. In order to facilitate the detection of some special functions (such as temperature, rotational speed, etc.), some automobile digital multimeters, in addition to these basic functions, are accompanied by some special accessories. Such as thermocouple adapter, thermocouple probe, vacuum / pressure converter, inductive current test clip, backlight display function and so on.
⑴Thermocouple adapter, thermocouple probe.
The thermocouple adapter and thermocouple probe can be used to detect the temperature of some parts of the automobile, so as to analyze and judge the possible cause of the failure through the change of temperature.
Figure 1. The schematic diagram of the basic automobile digital multimeter.
⑵Vacuum / pressure converter.
The vacuum / pressure converter can be used to detect the vacuum / pressure in some parts of the vehicle, so as to analyze and judge the possible cause of the failure by the change of the vacuum / pressure.
⑶Inductive current test clamp.
Figure 2 is a more commonly used diagram of Hall current inductive current test clip, which can be used to detect the Hall current in some parts of the vehicle, so as to analyze and judge the possible cause of the failure through the change of Hall current.
⑷Backlight display function.
Some automobile digital multimeter also has backlight display function, is used to make the display data in the dark light can also see the reading.
Third, issues to be clarified.
The digital multimeter should be used as far as possible to detect the special electrical devices and related parameters such as rotational speed duty cycle frequency pressure temperature time and closing angle in the automobile especially in the electrically controlled vehicle.
This article is from Allicdata Electronics Limited. Reprinted need to indicate the source.