milliampereméter

A milliampereméter is an electrical instrument used to measure electric current in milliamperes. A milliampere is one-thousandth of an ampere, a standard unit of electric current. These devices are essential for testing and troubleshooting electronic circuits where currents are typically small.

Milliamperemeters often operate on the principle of electromagnetism, similar to ammeters that measure larger currents. They typically contain a coil of wire through which the current to be measured flows. This current creates a magnetic field that interacts with a permanent magnet, causing a needle to deflect across a calibrated scale. The amount of deflection is proportional to the current.

Modern milliamperemeters can be analog, displaying current on a physical needle, or digital, showing the reading on an LCD or LED screen. Digital meters generally offer higher precision and ease of reading. They are commonly found as part of a multimeter, a versatile tool that combines the functions of a voltmeter, ohmmeter, and milliamperemeter.

When using a milliamperemeter, it must be connected in series with the circuit component through which the current is to be measured. This ensures that all the current passes through the meter's internal resistance. Care must be taken to select a meter with an appropriate range to avoid damage to the instrument or the circuit being tested.