Manifold gauges are specialized tools utilized in HVAC/R system evaluation and repair. They are divided into three sections, two for low and high pressures and one utility section. They are made of brass or aluminium, with special connections drilled through a device. Gauges may be presented in analog or digital form. Older models have analog measuring devices, however they may be inaccurate due to pointer defects or incorrect readings made by servicing technician. Their digital counterparts display in-depth detailed information, however they may have settings variating from one manufacturer to another, and that can make servicing and repairing difficult.

To operate this device you have to get low and high pressure connections attached to the system outlets. The utility section is purposed for ventilation hoses, also you can attach tanks with refrigerant or other gases if you wish to vent or refill the system. After the tool is attached to the system you can open the valves and monitor the pressure in different sections of the tool.