What does a compound pressure gauge primarily measure?

A compound pressure gauge is designed to measure both pressure and vacuum, which makes it particularly versatile for applications involving various types of fluids and gas systems. This gauge typically features a dual scale, allowing it to provide readings in psi or other pressure units for both positive pressures and negative pressures (vacuum).

The ability to measure vacuum is essential for systems that may operate below atmospheric pressure, such as refrigeration and air conditioning systems. Having a gauge that encompasses both pressure ranges is critical for technicians who need to monitor and troubleshoot these systems effectively.

While some other gauges may focus solely on absolute pressure or atmospheric pressure, the distinctive feature of a compound pressure gauge is its capability to provide insights into both domains, making it an invaluable tool in HVAC applications.