How to Hook up an Amp Meter

An amp meter (also called an ammeter) is a device that measures the current in an electrical circuit. Current, measured in amperes, or amps, is essentially the rate at which electrons pass through a specific point in the circuit. Amp meters use the electromagnetic field generated by the current to move a needle or change a digital display. Most modern amp meters perform a variety of electrical measurements and are therefore known as multimeters.

Things You'll Need

• Electrical circuit
• Amp meter
• 2 Leads with alligator clips

Instructions

1. Analyze the circuit to which you wish to connect the amp meter. The current in a circuit flows from the positive battery terminal to all the devices in the circuit and back to the negative battery terminal. In order to ensure a correct reading, the positive lead of the amp meter must receive the higher voltage; connect the amp meter's positive lead to the positive end of the circuit (near the positive terminal), and connect the negative lead to the negative end of the circuit.

2. Examine the amp meter's terminals for measuring amp flow, or amperage. A commercial multimeter should have a specific input for amperage, typically labeled "A." Plug the positive lead of the amp meter (usually marked "+") into this terminal. The meter should only have one negative terminal for all electrical measurements, usually labeled "COM" for "common ground." Plug the negative lead (marked "-") into this terminal.

3. Select the highest amperage range on the amp meter to avoid overloading it with a current it's not prepared to handle. A multimeter will have a variety of settings on the selector dial. You'll need to choose one of the amperage settings to indicate that you'll be measuring amperage, as opposed to voltage or resistance.

4. Disconnect the positive lead from an electrical device in the circuit and connect it to the probe from the amp meter's positive terminal. Connect the probe from the meter's negative terminal to the positive terminal of the electrical device.

5. Turn the amp meter on and read the display. You may need to select a lower amperage range to find a setting that will allow a value to register on the display. Determine the correct units of measure from the selected amperage range on the multimeter.

References

• Kaito Electronics