What is a multimeter used for in HVAC systems?

A multimeter is a vital tool in HVAC systems primarily because it measures various electrical properties such as voltage, current, and resistance. These measurements are crucial for HVAC technicians to troubleshoot electrical components, check the performance of motors, verify circuit integrity, and ensure that systems are operating within their electrical specifications.

Understanding how to use a multimeter enables technicians to diagnose issues effectively. For instance, measuring voltage can help ascertain whether an electrical supply is adequate for components to function. Measuring current aids in evaluating if the system is drawing the appropriate amount of electricity, which can indicate motor issues or other electrical faults. Resistance measurements can help identify issues with components like wiring and connections.

The other choices focus on different aspects of HVAC systems. Measuring temperature and humidity is important for comfort and system performance but falls outside the multimeter's capabilities. Similarly, calculating airflow and pressure or diagnosing refrigerant levels involves equipment specifically designed for those tasks, not a multimeter. Thus, the multimeter's ability to measure essential electrical properties makes it an indispensable tool in HVAC service and maintenance.