An instrument that measures potential differences between 2 points in an electrical circuit is called?

The instrument that measures potential differences between two points in an electrical circuit is known as a voltmeter. This device is specifically designed to quantify the voltage, which is the potential energy per unit charge, allowing technicians and engineers to assess how much electrical potential is present in a circuit.

Voltmeters typically have high internal resistance to ensure that they do not significantly alter the circuit's characteristics when measuring voltage, which is crucial for obtaining accurate readings. They are widely used in HVAC systems for troubleshooting and ensuring that components operate as intended.

In contrast, a potentiometer is primarily used to measure the voltage by creating a variable resistor, while a thermistor is a temperature-sensitive resistor and not designed for measuring electrical potential. An ohmmeter is meant to measure resistance in a circuit, not potential differences. Understanding these distinctions helps in selecting the correct instrument for specific electrical measurements and troubleshooting tasks in HVAC applications.