Measurement of digital multimeter current in automobile circuit
If there is an error in the measurement of the current, it will cause damage to the digital multimeter, making it damaged and unusable. Then, in the process of using the digital multimeter to measure the current in the car circuit, the measurement must be carried out in accordance with strict measurement procedures, otherwise the digital multimeter will be burned.
When using a digital multimeter to carry out current measurement, at the very beginning, the gear and range of the digital multimeter should be selected in the area of the current gear. First of all, the maximum range of the current should be selected, and adjusted according to the actual measurement results in the later stage. The red test lead of the digital multimeter should be inserted into the red jack of the digital multimeter according to the actual situation, and the black test lead should be inserted into the COM jack like the above voltage measurement. Between the circuit to be measured and the digital multimeter, a fuse with a rated current smaller than the fuse of the digital multimeter itself should be selected, and this fuse should be used to connect the multimeter pen and the measuring circuit in series. When the rated current of the fuse is 20A, the fuse that can be selected must be less than 20A, including 15A and 10A. Because in the process of measurement, the digital multimeter may burn out due to excessive current.
When measuring, it is necessary to observe the state of the fuse in series. If the fuse is blown, there may be a certain fault in the measured circuit. This fault must be detected in a professional way. At this time, the digital multimeter should be disconnected from the measured circuit, and then the series fuse and the two test leads of the digital multimeter itself should be connected in series at both ends of the measured circuit. The current value displayed in the display area of the digital multimeter measurement result is the current of the measured line. If the current value is less than 1A, it means that the current range selected at the beginning is relatively large. Then disconnect the measuring tools and move the red test lead to the socket of the smaller current gear, which will improve the accuracy of the current measurement value.
When using a digital multimeter to measure current, you must pay attention, because the current size of the measured object cannot be determined, then, at the beginning, you should choose an area with a larger current range for measurement, and then combine the size of the measured results later. The current gear is adjusted. The connection order of the measuring probes in the measuring circuit must be correct, and the current gear cannot be directly connected to both ends of the measuring circuit, otherwise the digital multimeter may burn out.
