The black iron casing electric contact pressure gauge is an economical industrial instrument that integrates pressure measurement, on-site indication, and electrical signal control functions. Its core features a black iron powder-coated casing, an electric contact control mechanism, and a Bourdon tube pressure sensing element. It emphasizes high cost-effectiveness and practicality, and is suitable for pressure monitoring and automatic control of non-corrosive, non-crystalline gas or liquid media. It is widely used in general industrial scenarios such as machinery, chemical, HVAC, and water supply.

The pressure of the measured medium enters the Bourdon tube, causing it to elastically deform. This deformation, via a transmission mechanism, deflects the indicating pointer, displaying the real-time pressure value on the dial.

When the indicating pointer touches the lower limit setting pointer as the pressure changes, the corresponding electrical contact closes, outputting an "on" signal. When the pressure rises to the upper limit setting pointer position, the upper limit electrical contact actuates, outputting an "off" signal.

The switching signals output by the electrical contacts can directly trigger alarm devices or control the start and stop of pumps and valves, achieving automatic pressure control and interlocking protection.