Meters

Meters are measuring instruments that switch between multiple functions to measure voltage, current, etc. They are also called "circuit testers". They are largely classified into analog and digital types; digital types feature higher internal resistance compared to analog types and are fit for testing both low voltage/resistance and high resistance. Boost gauges, "slim style" RPM meters, voltage meters, watt-hour meters, and more are available. Materials used include steel, ceramic, ABS resin, acrylic resin, etc. Meters differ in whether they measure alternating current or direct current, or by the size of wires measured, and must be selected to suit the application. The frequency band, current range, whether the meter has testing functionalities, etc., must also be considered.