While designing any electronic circuit, the knowledge to use multimeter is essential. A multimeter is a single meter that is used to measure voltage, current, resistance and capacitance. A multimeter uses negative (black) and positive (red) probes.
To measure resistance, multimeter should be set to resistance mode which is horse-shoe shaped icon. By keeping probes of multimeter at the ends of resistor, Resistance can be measured. Numbers displayed in multimeter's screen indicates the value of resistance in Ohm. To measure capacitance, multimeter is kept in capacitance mode (it shows curved line and vertical line). Measured reading is noted in farads.
Multimeter can be used to check the continuity in the connection of a circuit. First, Mulimeter should be kept in setting which shows series of diminishing curved lines. Continuity is indicated with a beep tone. If any broken connection, no beep sound can be heard.
To measure AC voltage, multimeter is set to VAC and for DC voltage, it is set to VDC. Checking diodes can be done by setting multimeter to diode check symbolized with an arrow against vertical line. Positive probe (red) of multimeter is placed on anode of diode and negative probe (black) is placed on cathode of diode. After making a tone, multimeter displays voltage drop across the diode and voltage ranges from 0.5V to 0.75V.
To measure AC current, multimeter is set to AAC (A~) and to measure DC current, it is set to ADC(A=). Negative probe should always be connected in the terminal named “COM”(common) and positive probe is connected on the basis of low or high current measuring. Both AC and DC current are measured in amps.