Which tool is primarily used to measure refrigerant pressure in an HVAC system?

The manifold gauge set is the correct choice for measuring refrigerant pressure in an HVAC system. This tool is specifically designed to connect to the service ports of the HVAC unit, allowing technicians to assess both the high and low side pressures of the refrigeration system. The gauges display the pressure readings, which are essential for diagnosing the system's performance, checking for leaks, and ensuring proper refrigerant levels.

Understanding the pressures in the system is critical for effective troubleshooting and maintenance, as they can indicate whether the system is functioning correctly or if there are issues such as overcharging, undercharging, or blockages. The manifold gauge set typically consists of two pressure gauges, hoses, and various fittings, making it a versatile and indispensable tool for HVAC professionals.

Other options, like a thermometer, are used for measuring temperature but do not provide pressure readings specific to refrigerants. A digital multimeter is mainly utilized for electrical measurements, while a pressure switch is a component within the system that may activate based on pressure changes, but it does not directly measure pressure in a way that allows technicians to read and analyze it during servicing.