Bar graph arrays are light emitting diodes (LEDs) that are used for solid state metering in applications such as audio monitoring, telecommunications, and instrumentation

Digital bargraphs measure process and electrical variables such as pressure, flow, temperature, speed, current, and voltage.

Digital panel meters measure and display processes and electrical variables via an alphanumeric digital readout.

Digital multimeters (or multi-meters) are used to measure electrical quantities such as voltage, current, resistance, frequency, temperature, capacitance, and time period measurements.

Digital voltmeters are instruments that measure voltage or voltage drop in a circuit.

Digital ammeters are instruments that measure current flow in amperes and display current levels on a digital display.

Digital resistance meters are instruments that measure electrical resistance.