万用表应用技巧（Multimeter application skills）.docVIP

万用表应用技巧（Multimeter application skills） Multimeter application skills First, no road detection This method is carried out when the IC is not welded into the circuit. In general, the positive and reverse resistance values of each pin corresponding to the ground pin can be measured by a multimeter, and compared with the intact IC. Two 、 road detection This is a multimeter used to check the IC pins in the road (IC in the circuit), DC resistance, ground AC and DC voltage, and the total operating current detection method. This method overcomes the limitation of the substitution test method and the limitation of the replaceable IC and the trouble of removing the IC. It is the most common and practical method to detect the IC. 1. in the road DC resistance detection method This is a multimeter, Ohm gear, directly on the circuit board to measure the IC of each pin and peripheral components of the forward and reverse DC resistance values, and compared with the normal data to detect and determine the failure method. When measuring, pay attention to the following three points: (1) switch off the power before measuring to avoid damaging the meter and the component in the test. (2) the internal voltage of the resistance of the multimeter shall not be greater than 6V, and the range shall be preferably R x 100 or R * 1K block. (3) when measuring the parameters of the IC pin, we should pay attention to the measurement conditions, such as the models to be tested, the position of the sliding arm of the potentiometer related to the IC, and also the quality of the external circuit components. 2. measuring method of DC working voltage This is a case of electricity, DC voltage with a multimeter measuring gear working voltage on DC supply voltage and external components; to test the IC pin on the DC voltage value, and compared with the normal value, and then compress the fault coverage, find out the damaged elements. When measuring, pay attention to the following eight points: (1) the multi