A few things to remember when testing digital multimeters
Digital multimeter should be calibrated regularly, calibration should be used in the same type or higher precision digital instruments, according to the first school DC block, and then the school AC block, * after the school capacitance block of the order of the order of abort.
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Ø about high resistance, resistance test results and pointer meter test results are different from the normal. It is normal that the test results of resistance are different from the test results of pointer meter, which is firstly due to the slight difference of the test premise.
Ø When testing the physical quantity related to polarity, the polarity display corresponds to the meter pen. That is to say, when the polarity is not shown, the red pen touch point is the potential ** or current inflow end, and when the polarity is shown as "-", the red pen touch point is the low end of the potential or current outflow end.
Ø Electrical resistance and diode block is different from the pointer meter. When measuring the resistance of pointer meter, the red and black pens are opposite to the polarity of the test source, i.e. the black pen is the positive end of the test source and the red pen is the negative end. While the digital table with the test source polarity differences, that is, the red pen for the test source positive end, black pen for the negative end, which reveals the voltage and current blocking divergence. This will not be mixed up, which is better than the pointer meter.
Ø Regarding the triode that does not know the polarity or the order of the pins, it can be detected by changing the pin several times in the triode hfe block to distinguish and determine the electrodes of the triode.
Ø Calibration.
