Adjustable vacuum pressure switch adjustment method

The adjustment methods of adjustable vacuum pressure switches usually involve setting pressure thresholds, verifying the accuracy of actions, and conducting necessary calibrations. The following are the detailed steps and key points:

1. Preparations

Confirm the type of switch: Clearly understand the adjustment method of the adjustable vacuum pressure switch (such as knob adjustment, screw adjustment or electronic adjustment), and be familiar with its adjustment range and accuracy.

Safety check: Ensure that the switch is in the power-off state to prevent electric shock or misoperation during the adjustment process.

Tool preparation: Prepare appropriate tools according to the adjustment method, such as screwdrivers, wrenches or calibration equipment.

2. Set the pressure threshold

Adjust the starting pressure (operating pressure) :

Find the pressure adjustment knob or screw on the switch, which is usually marked with "SET" or "Pressure Adjustment".

Turning the knob or screw clockwise increases the starting pressure, while turning it counterclockwise reduces it. For example, if the starting pressure needs to be set at -80 kpa, slowly rotate the knob until the pressure gauge shows a value close to this.

Adjust the stop pressure (reset pressure) :

Some switches can adjust the stop pressure independently, usually through another adjusting knob or screw.

The stop pressure should be lower than the start pressure to form a hysteresis range to avoid frequent starts and stops. For example, set the stop pressure to -90 kpa and ensure a difference of 10kPa from the start pressure.

3. Verify the accuracy of the action

Simulation of pressure changes

Use a vacuum pump or a manual air extraction device to slowly change the system pressure and observe the operation of the switch.

When the pressure reaches the starting pressure, the switch should be triggered (such as when the contacts close or open) and a signal should be sent.

When the pressure drops to the stop pressure, the switch should reset (the contacts return to their initial state).

Record action values:

Record the pressure value when the switch is actually operating and compare it with the set value.

If there is a deviation, fine-tuning is required until the action value is consistent with the set value.

4. Fine-tuning and calibration

Fine-tuning method:

If there is a slight deviation between the switch action value and the set value, it can be fine-tuned by slightly rotating the adjustment knob or screw.

After each fine-tuning, the accuracy of the action needs to be reverified to avoid excessive adjustment.

Calibration steps:

Calibrate the switch using a standard pressure gauge to ensure its measurement accuracy.

Multiple tests were conducted at different pressure points (such as -100 kpa, -80 kpa, -60 kpa, etc.), and the pressure-action curve was plotted.

Adjust the set value or compensation parameters of the switch (such as temperature compensation, linear compensation, etc.) according to the calibration results.

5. Fixation and testing

Fixed adjustment components:

After the adjustment is completed, fix the adjustment knob or screw with a lock nut or glue to prevent it from loosening due to vibration or during use.

Long-term stability test

Let the switch operate continuously for several hours or days at the set pressure and observe whether its operation is stable and reliable.

Record the number of actions and pressure changes of the switch, and evaluate its service life and reliability.

6. Precautions

Avoid overpressure: During the adjustment process, ensure that the system pressure does not exceed the pressure resistance range of the switch to prevent damage to the switch.

Prevent misoperation: During the adjustment or testing process, avoid applying shock or vibration to the switch to prevent its misoperation.

Recording and archiving: Record and archive the adjustment parameters, calibration data and test results to facilitate subsequent traceability and management.

7. Common Problem Handling

The switch does not operate:

Check whether the power supply is connected and whether the signal lines are connected correctly.

Check whether the system pressure has reached the start-up pressure.

Check whether there are impurities or blockages inside the switch.

The switch operates inaccurately.

Recalibrate the switch and adjust the set values or compensation parameters.

Check whether the adjusting components are loose or damaged.

The switch starts and stops frequently:

Increase the difference between the starting pressure and the stopping pressure (hysteresis interval).

Check whether there are pressure fluctuations or leaks in the system.