Analog multimeters are instruments that are used to measure electrical quantities such as voltage, current, resistance, frequency and signal power. Basic functionality includes measurement of potential in volts, resistance in ohms, and current in amps. Analog multimeters are used to find electronic and electrical problems. Advanced units come with more features such as capacitor, diode and IC testing modes.
Specific measurements made by analog multimeters include DC voltage, AC voltage, DC current, AC current, frequency range for AC currents, and decibel measurement. Analog multimeters that measure current may have a current clamp built-in or configured as a probe. A current clamp is a sensor that clamps around the wire. When searching for analog multimeters it is important to consider the measurement range for whichever value is being measured. An analog multimeter displays these values via a dial, typically a moving pointer or needle. Analog multimeters are generally bench top or hand held. Bench top models can also be portable by use of handles and wheels. Hand held multimeters are specifically designed to be used while holding, i.e., can be operated with one hand.
Common features for analog multimeters include battery power, overload protection, temperature compensated, mirrored scale, range switch, diode test, and battery test. Devices with battery power can be operated without plug in power. Multimeters with overload protection have a fuse or other method to protect meter. Temperature compensated devices have programming or electrical devices designed to counteract known errors caused by temperature changes. A mirrored scale makes it easier to read the instrument to a given accuracy by enabling the operator to avoid parallax errors. A range switch is used to select appropriate range of units to be measured. A device with a diode test has methods for testing diode operation. A device with a battery test has methods for testing battery operation. An important environmental parameter to consider when searching for analog multimeters is the operating temperature.