万用表2（Multimeter 2）.doc

万用表2（Multimeter 2） Digital multimeter uses 2009-06-11, 18:20 now digital measuring instruments have become mainstream, there is a trend to replace analog instruments. Compared with analog instrument, digital instrument has high sensitivity, high accuracy, clear display, high overload capacity, easy to carry and easy to use. Take VC9802 digital multimeter as an example, briefly introduce its using method and matters needing attention. (1) using method A before use, should carefully read the relevant instructions, familiar with the power switch, range switch, Jack, special socket role B puts the power switch in the ON position. C DC voltage measurement range: according to the need to switch to DCV (DC) or ACV (AC) in the appropriate range, the red pen is inserted into the V / Omega hole, the black pen is inserted into the COM hole, and the pen and the measured line in parallel, the reading is displayed. D AC DC current measuring range: switch to DCA (DC) or ACA (AC) in the appropriate range, the red pen is inserted into the hole (mA 200mA) or 10A ( 200mA) hole, the black pen insertion hole COM, and the multimeter circuit can be measured in series. When measuring direct flow, digital multimeter can display polarity automatically. Measurement of the resistance of the E: the appropriate range range switch to OMEGA / Omega, the red pen is inserted into the V hole, the black pen insertion hole COM. If the measured resistance exceeds the maximum of the selected range, the meter will show 1, and a higher range should be selected. Measurement of resistance, the red pen is positive, the black pen is negative, and this is the opposite of pointer multimeter. Therefore, measurement of transistor, electrolytic capacitors and other polar components, must pay attention to the polarity of the pen. (2) Notice for use A if it is impossible to estimate the magnitude of the voltage or current to be measured in advance, it should be first measured at the highest range and then gradually