Which device is used to measure the pressure of refrigerant in HVAC systems?

The manifold gauge set is the correct choice for measuring the pressure of refrigerant in HVAC systems. This tool typically consists of two gauges: one for measuring high pressure and another for measuring low pressure. By connecting the hoses from the manifold gauge set to the appropriate service ports on the refrigeration system, technicians can read the pressure of the refrigerant, which is essential for diagnosing system performance and ensuring it operates within the manufacturer's specifications.

In HVAC systems, accurate pressure readings are critical for assessing the system's refrigerant charge, detecting leaks, and ensuring that the system is functioning efficiently. The manifold gauge set provides both high-side and low-side pressure readings, allowing for comprehensive analysis and troubleshooting.

Other devices listed, such as thermocouples, clamp meters, and amperage meters, serve different purposes. A thermocouple measures temperature, while a clamp meter measures electrical current. An amperage meter also focuses on current measurement. These tools may be important in HVAC diagnostics, but they do not provide information about refrigerant pressure, which is the specific requirement in this scenario.