What are the gauges called that can be mounted inside the downdraft spray cabin to help maintain positive pressure?

The gauges that can be mounted inside a downdraft spray booth to help maintain positive pressure are known as manometers. These devices measure pressure differences, allowing users to monitor the pressure within the spray booth environment effectively. Maintaining positive pressure is crucial in a downdraft spray cabin, as it helps to prevent contamination from outside air, ensuring a cleaner and safer environment for painting and refinishing tasks.

Manometers operate by comparing the pressure inside the spray booth to the atmospheric pressure, giving a clear indication of how well the ventilation system is functioning. This ensures that the airflow is adequate to remove overspray and other particulates from the booth.

Other types of gauges listed, such as barometers, which measure atmospheric pressure; thermometers, which measure temperature; and hydrometers, which measure the specific gravity of liquids, do not serve the purpose required for maintaining pressure in a spray booth environment. Thus, manometers are the appropriate choice for this application.