A digital multimeter is a single instrument that is capable of measuring voltage, current, and resistance, so it is useful for troubleshooting electrical circuits and equipment. Voltage measurements can be made between any two arbitrary points in a circuit or relative to a single absolute ground point. Either method can be used to isolate component performance problems within a circuit.
Current measurements with a multimeter require incorporating the meter into a circuit, so they are more difficult to make. Voltage and current measurements require that a circuit be energized. Resistance measurements require that the power be off and the tested component isolated from the rest of the circuit.
Learning Objectives
At the end of this module, you will be able to:
- List precautions to be taken when making electrical measurements
- Describe a digital multimeter
- List what quantities can be measured with a multimeter
- Explain two methods of measuring voltage
- Describe how voltage can be used to detect bad components in a circuit
- Describe how resistance can be used to detect bad components