A Legget is used to measure what?

A Legget, also known as a leg meter or Legget meter, is specifically used to measure resistance in electrical circuits. Resistance is a measure of how much an object opposes the flow of electric current. The Legget operates by applying a known voltage across a resistor and measuring the resulting current flow, thus allowing it to calculate the resistance using Ohm's Law.

Understanding resistance is crucial in HVACR systems since it affects how efficiently components like motors and heating elements operate. Correctly measuring resistance ensures that circuits are functioning properly and helps in troubleshooting issues related to circuit integrity and performance.

In the context of the other choices, while various instruments are designed for measuring voltage, current, and power, those do not apply to the Legget. Voltage is measured with a voltmeter, current with an ammeter, and power with a wattmeter. Each of these tools serves a different purpose in electrical diagnostics and analysis, but the Legget is uniquely focused on resistance.