Mechanical pressure switches are usually supplied with a factory-set switch point. Nevertheless, some users desire to get this to configuration themselves, as, for instance, the pressure conditions in the application form can change. Regarding pressure switches with a measuring aspect in a bellows, diaphragm or piston design, the manual setting of the switch point, reset point or hysteresis (according to the model) requires a specific amount of effort. Nonetheless it?s เกจวัดแรงดัน . This short article explains, step-by-step, how to do it.
Users need the following equipment: a pressure source (e.g. a dead-weight tester), a control pressure gauge, a continuity tester or perhaps a control lamp as well as a tool for the adjustment screw (by the way, WIKA supplies the correct Allen key with its instruments; a conventional screwdriver is sufficient for setting the hysteresis).
Setting plan view for the model PSM02 mechanical pressure switch from WIKA. The pin assignment 1 and 3 (small picture) corresponds to the switching function ?normally closed?, the assignment 2 and 3 would be for ?normally open?.
Setting of the switch point
First, screw the pressure switch in to the pressure source connection and connect its electrical connections to the continuity tester or control lamp.
Turn the adjustment screw for the switch point in completely. This sets the switch point to the highest possible value.
Now apply the desired switching pressure to the pressure switch before control pressure gauge indicates the worthiness.
From then on, turn the adjustment screw out until the instrument switches and the continuity tester or the control lamp reacts.
Then lower the pressure before pressure switch switches back and increase it again to check on the switch point. If necessary, the switch point should be corrected by turning the adjustment screw. Repeat the procedure before desired switch point is reached.
Setting of the reset point
In a few applications, the reset point is defined rather than the switch point, e.g. for minimum pressure monitoring. Here the task is similar to the switch point, but without submiting the adjustment screw.
Increase ไดอะแฟรม ซีล before instrument switches.
Then lower the pressure until the instrument switches back and adjust the position of the adjustment screw accordingly. The guideline here is:
Set point < Actual value: Turn the screw out
Set point > Actual value: Turn the screw in
Setting of the hysteresis (not with all models)
To do this, first set the switch point and then check the reset point (see above). According to the reset point, the hysteresis screw is turned in or out. The switch point must then be checked, as changes to the hysteresis screw also affect the switch point.
Note
digital pressure gauge of the various mechanical pressure switches as well as further technical information can be found on the WIKA website. When you have any questions, your contact will gladly assist you to.
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