When using resistance and line on-off test mode of the automotive digital multimeter.

Last Update Time: 2019-04-22 14:33:41

1.When using OTC700 series automotive digital multimeter to test resistance and circuit on-off, the basic principle of choosing gear and connecting detection circuit is basically the same as the above voltage measurement and will not be repeated. But in the process of continuous measurement, if the circuit path is normal and the line has no breaking point, the "beep" sound from the multimeter can be heard, and the display lamp will also be on at the same time; if the line has a breaking point, the "beep" sound from the multimeter will not be heard, and the display lamp will not be on.      


2. When using the diode test mode, the correct method of choosing the gear and connecting the detection circuit is adopted.           

When the rotary switch is in the ohm block, after choosing the polar tube test mode, one end of the black joint is inserted into the COM port of the human body, and the other end of the red joint is inserted into the N port of the human body. In this way, the other end of the black and red connector can be used to detect the diode.


 When detecting the electrode, the positive and reverse detection should be carried out once, and the method of detection and judgment is basically the same as that of ordinary digital multimeter.


3.When using the ampere test, properly select the method of blocking and connecting the detection circuit. # when using the OTC700 series digital multimeter for ampere testing, the method of selecting the stop and connecting the detection line is basically the same as that of the voltage shift, and is not described much.


4. Use the battery blocking test to correctly select the blocking and connection detection circuit methods. # OTC700 series of automobile digital multimeter battery (Battery Drain) test, can be used to continuously detect the battery leakage after the car ignition and related devices power down, the battery negative pole lap wire disconnected. Connection detection time is allowed to reach 30min. 


I. Selftuning method for blocking. 

OTC700 series of automotive digital multimeter battery (Battery Drain) block test has automatic correction function, the correction time is about a few seconds, and then automatically placed in the battery test position.

(1) the method of connecting the detecting circuit. When the battery negative lap wire is disconnected, connect the red connector to the disconnected cable, and the black connector to the battery negative, and then observe the display light on the meter. The indication of the display lamp is compared with the situation listed in Table 1 to determine the leakage of electricity. In the case of serial numbers 2 and 3, you should look for power leaks and troubleshoot them.

Table 1 shows the relationship between the condition indicated by the lamp and the leakage.

Serial   number

Display   light indication

Leakage   of electricity

Serial   number

Display   light indication

Leakage   of electricity

Serial   number

Display   light indication

Leakage   of electricity



Leakage   is low



The   leakage is at the edge



Leakage   is high


5. There are several modes that can be measured using an electrical (Electrical) block.

 When the OTC700 series digital multimeter rotary switch is placed in the electrical (Electrical) gear for measurement, it can be used to measure the tie-in (Ground), the charging system (Charging System) and the duty ratio (Duty) in three modes. The test method of duty cycle (Duty) mode is basically the same as that of voltage shift mode.


6. The basic function of electrical (Electrical) tie-in iron mode and the problems that should be paid attention to when testing.

 OTC700 series automotive digital multimeter electrical (Electrical) gear tie-in mode is used to detect the connection of any cable connected to it on the vehicle. It is determined whether the connection is good by measuring the voltage drop of a cable connected to the connected part and judging the connection by means of the highlight indication of the Good display lamp.

The two detected connectors of the multimeter are connected to the detected cable when the connection is performed, and if the connection is good, it is indicated by the highlight of the Coode display light.

 It must be noted that when detecting charging or starting circuit connections from a battery, it should first be connected to the battery connector rather than the battery connector. Because of the high incidence of corrosion failure on the joints and connector surfaces, it is often the root cause of the problem.

This article is from Allicdata Electronics Limited. Reprinted need to indicate the source.