What type of pressure do manifold gauges measure?

Manifold gauges measure pressure in relation to a known point, which is typically atmospheric pressure. This measurement is essential in various applications, especially in HVAC systems and refrigeration, where understanding the pressure within the system can provide valuable insights into its performance and operational efficiency. When the gauges indicate a value above atmospheric pressure, it is noted as positive pressure, while a value below atmospheric pressure indicates a vacuum or negative pressure. By comparing these pressure readings to atmospheric pressure, technicians can deduce critical information about the system's status, diagnose issues, and make necessary adjustments.

The concept of pressure measurements in manifold gauges is key to effective troubleshooting and maintenance in systems that rely on the principles of thermodynamics and fluid mechanics. Therefore, understanding that they measure pressure compared to a known point is fundamental for anyone working with these tools.