How to Use an Analog Meter

An analog meter has a needle that moves along a scale to indicate the measurement's value. According to the book, "Using Your Voltmeter," analog meters are also known as a volt or ohm meter, VOM (Volt-Ohm-Milliammeter), multimeter, or multitester. Controls and switches on the meter's front must be set to perform the necessary test correctly. There are also jacks that accept test leads that connect the meter to a component. Properly used, a meter can help you diagnose broken or poor connections, power loss, faulty parts and other issues.

• 1

  Attach the red probe, the positive side, and the black probe for the negative jack to your voltmeter. According to "Using Your Voltmeter," when testing DC voltage or amps, match the positive probe and terminal. Matching is unnecessary for AC testing. Hold the probe tips tightly against the contact but avoid touching the metal with the fingers.

• 2

  Make sure the needle falls to the zero position before you begin measuring a component. If the needle fails to return to the zero position on the scale, locate the zero adjustment screw on the meter. Gently adjust the screw until the needle falls to the zero. If you damage the screw, it will permanently damage the spring responsible for moving the needle, warns "Using Your Voltmeter."

• 3

  Check for continuity in the meter by touching the two leads together. The needle should move to zero.

• 4

  Select the proper test function, such as ohms, and scale. Touch the two probes to the wiring or circuit board and check the meter reading.

• 5

  Choose the lowest scale that is higher than the resistance you are checking. If you set it too low, you'll overload the meter. When you are testing for volts or amps, the live circuit powers the meter. In ohms and continuity, the meter's batteries provide a weak current for the test.

• 6

  Test a small appliance. Unplug the appliance and set the meter to test ohms with an auto-ranging scale. The probes touch the power plug prongs. You can use alligator clips to attach the probes to the cord. Turn on the meter and press the appliance's switch. According to Family Handyman, a reading of infinity or 0.L. indicates a bad or dirty switch.

• 7

  Test an extension cord similarly to testing a small appliance. The settings remain the same, but you use a jumper wire on the cord's prongs to create a closed circuit. Place the probes in the other end and activate the meter. Infinity represents a broken wire.

• 8

  Test a wall switch. Know that this can be dangerous. Shut off the main power at the electrical box. Disconnect one wire terminal at the switch. Use the ohms function and X-1 scale. Hold the probes steady on each terminal and activate the meter. Polarity is irrelevant. The wall switch is bad if your meter reads infinity on each wire.