Note the main selector wheel on the front of the multimeter. Use this wheel to select the function you need and the sensitivity of the measurement you're going to make. You'll notice three jack inputs arranged in a vertical line on the bottom right. They are marked – from top to bottom – 10ADC, VΩmA and COM. The meter comes with a pair of leads, one black and one red, that fit into these jacks. On the left side, you'll see a multipin transistor /hFE jack for testing transistors.

You'll also see an On/Off button. Turn this on to activate the LED display. Measuring Voltage and Current. To measure current, switch the red lead to the 10 ADC jack and leave the black one in the COM jack.

Turn the dial to the 10 amp (10A) area, make sure the meter is on, touch the leads to the exposed circuit wires and note the reading. If it's below 0.2 amps, turn off the meter, place the red lead into the VmA jack and turn the dial one position counterclockwise to the 220m setting in the DC amp (DCA) area. Turn on the meter and take another reading. Continue turning the dial counterclockwise – all the way to 200 µ if necessary – to increase the accuracy of the reading. Measuring Resistance and Continuity. When you measure resistance, the unit supplies a small current, so there must be no other current source.

Check the circuit with the voltage function to make sure the meter reads 0. Insert the red lead in the VΩmA jack and the black lead in COM. Turn on the multimeter and move the selector to the 200 position in the ohm (Ω) area.

Before you take a measurement, touch the leads together and make sure the meter reads 0, indicating there is no resistance between the leads. Touch the leads to the exposed circuit wires and note the reading. If the reading is 1, turn the dial one position counterclockwise and try again. Keep turning the dial – all the way to 2000k if necessary – until you get a reading other than 1.

You can use the multimeter to test the voltage drop across a diode so you can compare it to the diode's specifications and determine whether it's still good. The path of least resistance robert fritz pdf file. Turn the dial to the diode section, which is at the 6 o'clock position next to the lowest setting in the ohm section.

Insert the red lead into the VΩmA jack and the black lead into COM. Turn on the meter. Touch the red lead to one terminal of the diode and the black lead to the other and note the reading, which is displayed in millivolts. If the reading is 1, reverse the leads and try again.

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An electrically savvy handyman frequently carries a digital multimeter in his tool box or service vehicle. A properly used multimeter measures both voltage and current for alternating current, or AC. The multimeter also measures voltage and current for direct current, or DC. Electronic hobbyists can also test diodes, resistors and transistors with the Cen-Tech 92020 digital multimeter. Safety-conscious workmen and hobbyists receive prior instruction in the multimeter’s operation, as the device measures potentially deadly electrical voltages.

Measuring AC Voltage Place the red lead’s plug end into the jack marked “V-ohm-mA.” Place the black lead’s plug end into the jack marked “COM.” Set the multimeter to read AC voltage. Turn the range selector knob to the position marked “750 ACV.” Turn the meter on. Slide the power switch to the “On” position.