A negative pressure switch-also known as a vacuum switch-is an intelligent instrument that integrates negative pressure measurement, display, and control functions. It is characterized by simple operation, convenient installation, high precision, and robust functionality. This pressure switch features capabilities such as reverse control, time-delay control, pressure-loss protection, password protection, one-touch error zeroing, and multi-unit pressure switching; it is suitable for measuring various levels of vacuum and can be used in conjunction with a wide range of vacuum pumps.
A vacuum switch serves as an automatic pressure protection controller for vacuum systems. When the vacuum pressure within the system exceeds a predetermined setpoint, the controller automatically interrupts the electrical circuit and issues a signal to ensure the continued, proper operation of the system. Should the pressure within the system rise above or fall below the designated safe pressure range, the controller's internal pressure sensor activates immediately, causing the internal electrical contacts to switch (either connecting or disconnecting), at which point the equipment ceases operation. Conversely, when the system pressure returns to within the equipment's safe operating range, the pressure sensor immediately resets, switching the contacts back to their normal state and allowing the equipment to resume normal operation.
A mechanical vacuum switch operates based on purely mechanical deformation, which triggers the actuation of a microswitch. As pressure increases, the vacuum switch exerts force upon its pressure-sensing element-such as a diaphragm, bellows, or piston-causing it to deform and undergo upward displacement. Through a mechanical linkage system (typically involving levers and springs), this movement ultimately activates the uppermost microswitch, thereby generating an electrical output signal. In terms of functional principle, the configuration method for mechanical pressure switches is inherently based on continuous displacement; the setpoint can be configured as a single specific value, and certain models allow for the configuration of up to three distinct setpoints.