The pressure compensation principle of vacuum pressure switches

The pressure compensation principle of vacuum pressure switches mainly involves correcting the measurement errors caused by pressure changes in the vacuum system to ensure the accuracy and stability of the switch's operation. The core lies in enabling the switch to be reliably triggered or reset under different pressure conditions through a specific compensation mechanism. The following is the specific principle analysis:

1.The necessity of pressure compensation

Vacuum pressure switches are typically used to monitor pressure changes in vacuum systems and control the operation of equipment based on preset thresholds. However, the pressure in a vacuum system may be affected by various factors such as temperature, flow rate and leakage, resulting in a deviation between the actual pressure and the measured value.

The purpose of pressure compensation is to eliminate these deviations and ensure that the switch operates accurately within the set pressure range.

2. The implementation methods of pressure compensation

Mechanical compensation

Compensate for pressure changes through the elastic deformation of mechanical structures (such as springs, diaphragms, bellows, etc.). When the pressure changes, the deformation of the mechanical structure will adjust the position of the contacts, thereby compensating for the pressure error.

For instance, the diaphragm vacuum pressure switch senses pressure changes by the elastic deformation of the diaphragm and triggers or resets the contacts through a mechanical transmission mechanism.

Electronic compensation

The pressure signal is processed and corrected through the built-in electronic circuit or sensor. Electronic compensation can adjust the pressure threshold more precisely to adapt to different working environments.

For example, some vacuum pressure switches are equipped with microprocessors that can dynamically adjust the trigger points based on real-time pressure data.

3. The specific principle of pressure compensation

Pressure balance

There is usually a reference pressure chamber and a measurement pressure chamber inside a vacuum pressure switch. When the system pressure changes, the pressure in the measuring pressure chamber is compared with that in the reference pressure chamber.

By adjusting the pressure in the reference pressure chamber (such as through spring preload or electronic circuits), the changes in system pressure can be compensated, enabling the switch to operate at the set pressure threshold.

Hysteresis compensation

Hysteresis refers to the difference in the trigger points of a switch when the pressure rises and falls. By designing an appropriate hysteresis, the frequent operation of the switch due to pressure fluctuations can be avoided.

The pressure compensation mechanism can adjust the magnitude of hysteresis to adapt it to different working conditions.

Temperature compensation

Temperature changes can affect the pressure readings in the vacuum system. Some vacuum pressure switches are equipped with built-in temperature sensors that can automatically adjust the pressure threshold according to temperature changes, ensuring the accuracy of the switch.

4. Application scenarios of pressure compensation

Vacuum pump system

In the vacuum pump system, pressure compensation can ensure that the switch accurately monitors the vacuum degree when the pump starts, stops or the load changes, avoiding misoperation.

Vacuum packaging equipment

During the vacuum packaging process, pressure compensation can ensure that the vacuum degree inside the packaging bag reaches the set value, thereby improving the packaging quality.

Air tightness testing system

In air tightness testing, pressure compensation can eliminate the influence of environmental pressure changes on the test results and ensure the accuracy of the test.

5. Advantages of pressure compensation

Improve accuracy

The pressure compensation mechanism can significantly reduce measurement errors caused by factors such as pressure fluctuations and temperature changes, and improve the triggering accuracy of the switch.

Enhance stability

Through the compensation mechanism, the switch can still maintain stable performance under different working conditions, reducing the risk of misoperation or failure.

Extend service life

Reasonable pressure compensation can reduce the frequent operation of the switch and extend its service life.