Multimeter how to measure short circuit how to measure resistance
The use of multimeter :
(1) Familiarise yourself with the significance of the symbols on the dial and the main functions of the knobs and selector switches.
(2) Zero the meter mechanically.
(3) According to the type and size of the measurement, select the gear and range of the change-over switch and find out the corresponding scale.
(4) Select the position of the meter pen jack.
(5) Measuring voltage: Select the range when measuring voltage (or current), if you use a small range to measure a large voltage, there is a danger of burning the meter; if you use a large range to measure a small voltage, then the pointer deflection is too small to read. Range selection should try to make the pointer deflection to about 2/3 of the full scale.
(6) Measurement of current: when measuring DC current, place a changeover switch of the multimeter in the DC current block, and another changeover switch in the appropriate range from 50uA to 500mA, and the range selection and reading method of current is the same as that of voltage. Measurement must first disconnect the circuit, and then in accordance with the current from "+" to "-" direction, the multimeter connected in series to the circuit being measured, that is, the current from the red pen into the black pen from the outflow.
(7) Measurement of resistance: When measuring resistance with a multimeter, it should be done in the following ways*: a Select the appropriate multiplier block. b Ohm zeroing. Before measuring the resistance, the two pens should be shorted, while adjusting the "ohm (electrical) zero knob", so that the pointer is just pointing at the zero position to the right of the ohm scale.
If the pointer can not be adjusted to zero, it means that the battery voltage is insufficient or there are problems inside the instrument. And every time you change the multiplier block, you should carry out ohm zero adjustment again to ensure accurate measurement. c Reading: the reading of the meter head multiplied by the multiplication rate is the resistance value of the measured resistor.
