The Cen-Tech multimeter is an inexpensive digital multimeter solution with all of the basic functionality found on any other competing brand. The Cen-Tech multimeter is capable of accurately measuring alternating current voltage (ACV) as well as direct current voltage (DCV). The meter also allows the user to test the amount of resistance in a component or a circuit (in ohms). To use the device effectively, the probe wires must be inserted in the proper jacks based on what is being measured, and the dial must be turned to the correct measurement sector on the front panel of the multimeter.
Stretch out the two test probe wires next to the meter, doing so for both the red, positive (+) and the black, negative (-) probe wires. Make note of the metal ends of each wire. The short metal appendages are the plugs which slide into the jacks on the front panel of the multimeter, and the long, narrow appendages are the test probes which are touched to the circuit or component being measured.
Insert the plug of the black, negative (-) wire into the "COMM" jack of the multimeter, and insert the plug of the red, positive (+) wire into the "10ADC" jack to measure either AC or DC voltage. If measuring resistance or amperage, insert the plug of the red wire into the jack labeled "V(ohm)mA" jack instead, where the word "ohm" is actually the Omega symbol, a horseshoe-type emblem.
Turn the multimeter dial from "OFF" to the "ACV" section of the meter if measuring AC voltage, or "DCV" if measuring DC voltage. For these two, keep the red plug inserted in the "10ADC" jack. If you want to measure amperage rather than voltage, move the red wire plug to the "V(ohm)mA" jack and then move the meter dial to "DCA" (DC amperes) for measuring DC amps, or turn the dial to the "10A" position if measuring AC current amps up to 10 amps total.
Plug the red wire plug into the "V(ohm)mA" jack and set the dial to the panel section with the Omega symbol in it for measuring resistance in "Ohms."
When measuring any value of a circuit or component, be sure you understand the maximum value of that circuit or component in volts, amps or ohms. In all cases, if the multimeter doesn't have that exact maximum setting on the dial selector, always set the dial to the next-higher measurement value for the most accurate reading. If the dial is set to the next-lowest measurement value, you may not get a measurement reading on the display of the meter.
Never turn the dial of your Cen-Tech multimeter to the "DCV" or the "DCA" section when measuring AC voltage or AC amperage. Digital multimeters can be permanently damaged this way. Always be sure to set the meter to "DC" when measuring direct current, and "AC" when measuring alternating current.