How do common pressure switches work?
The working principle of the pressure sensor pressure switch: when the pressure in the system is higher or lower than the rated safety pressure, the disc in the sensor moves instantaneously, and the switch joint is pushed through the connection guide rod to turn on or off when the pressure drops When the rated recovery value is raised, the disc resets instantaneously, the switch automatically resets, or simply means that when the measured pressure exceeds the rated value, the free end of the elastic element is displaced, and the switching element is pushed directly or after a comparison to change the switch The on-off state of the element achieves the purpose of controlling the measured pressure. The elastic elements used in the pressure switch include single-turn spring tube, diaphragm, diaphragm box and bellows.
Classification of pressure switches for differential pressure sensors
Mechanical pressure switch
The mechanical pressure switch is a pure mechanical deformation that causes the micro switch to act. When the pressure increases, the deformation of the different sensing pressure components (diaphragm, bellows, piston) will move upwards, and through the mechanical structure such as the railing spring, the uppermost micro switch will finally be activated to output the electrical signal. SX50 pressure switch setting method is divided into continuous displacement type and force balance type from the functional principle.
Industrial pressure sensor electronic pressure switch
The other is the electronic pressure switch that has been popular on the market in recent years. It is used to replace electric contact pressure gauges and used in systems with high requirements for industrial control. This pressure switch has a built-in precision pressure sensor, amplifies the pressure signal through a high-precision instrumentation amplifier, collects and processes data through a high-speed MCU, and generally uses 4-bit LED real-time digital display pressure, relay signal output, and upper and lower limit control points can be set freely , Small hysteresis, anti-vibration, fast response, stable and reliable, high precision (accuracy is generally ±0.5%FS, high is ±0.2%FS), the use of hysteresis setting can effectively protect the repeated actions brought by pressure fluctuations, protection control The equipment is a high-precision equipment that detects pressure and liquid level signals and realizes pressure and liquid level monitoring and control. The characteristics are: the electronic display screen is intuitive, high precision, long service life, and it is convenient to set the control point through the display screen, but it is relatively expensive and requires power supply.
How does the low pressure switch work?
The pressure switch includes a low-pressure pressure switch, and its working principle is roughly the same. As follows: If there is no pressure switch and pressure gauge, the pump will run every time someone turns on the faucet, and put the water in the storage tank or pressure tank even a little bit. The pressure gauges in most residential systems are set to a maximum of 50 psi (PSI) and a minimum of 30 (PSI). When the pressure in the water tank drops to 30 PSI, the switch activates the pump in the well and allows more water to flow into the system. When the reading on the meter reaches 50 PSI, the switch is activated.
Switch operation
The switch is passive and does not require manual operation by the owner. Water pressure can do all this. When the pressure drops, the normally open contact closes, completing the circuit and starting the pump. When the set pressure is reached, the contact opens again, turning off the pump.
Some switches in the water pipe work together with the diaphragm pressing the piston and the spring inside the device. The spring pressure is set by the adjusting screw. Sufficient pressure on the diaphragm causes the switch to "close". When the pressure drops, the switch is activated.