10 Tips on How to Use a Multimeter
The basic principle of a multimeter is to utilize a sensitive magneto-electric DC ammeter (microammeter) as a meter head. When a small current passes through the head, a current is indicated. However, the meter head can not pass a large current, so it is necessary to connect some resistors in parallel and series on the meter head to shunt or step down the voltage, so as to measure the current, voltage and resistance in the circuit. Let the electrician's home editorial on the use of multimeter for you to do the introduction.
First, the voltage below 36V is safe voltage, when measuring higher than 36V DC, 25V AC, check whether the meter pen is reliable contact, whether it is correctly connected, whether it is well insulated, etc., so as to avoid electric shock.
Second, when changing function and range, the meter pen should leave the test point, and choose the correct function and range when testing, so as to prevent misoperation.
Third, DC voltage measurement, first turn the range switch to the corresponding DCV range, and then test the pen across the circuit under test, the red pen connected to the point of voltage and polarity displayed on the screen.
Fourth, AC voltage measurement, the first range switch to the corresponding ACV range, and then the test meter across the circuit under test.
V. DC current measurement, first turn the range switch to the corresponding DCA range, and then string the meter into the circuit under test.
Sixth, AC current measurement, the first range switch to the corresponding ACA gear, and then the meter series into the circuit under test.
Seven, resistance measurement, the range switch to the corresponding resistance range, the two pens across the measured resistance.
Eight, capacitance measurement, the range switch to the corresponding range of capacitance, the test meter across the measured capacitance, both ends of the measurement, if necessary, pay attention to the polarity.
Nine, the tube and on-off test, the range switch to set the gear. Connect the red meter to the diode positive pole, the black pen to the diode negative pole. Such as measuring the line of on-off, will be connected to the pen on both ends of the line to be tested, such as the buzzer is ringing the circuit is on, and vice versa, the circuit is off.
Ten, tube amplification measurement, the range switch is placed in the hFE file, decide to measure the transistor for the NPN-type or PNP-type, the emitter, base, collector were inserted into the corresponding hole.
