Calibrate Pressure Switch?

[Al Skierkiewicz]

Mark et al,
It is pretty obvious now that you have posted the pictures. The switch is using a standard snap action microswitch. These are not precision devices (the switch) and one must position the switch at a point where the lever will move enough to change the switch state. The hysteresis naturally occurs in the snap action mechanism of the switch. As the catalog page shows, the plunger moves when a specific pressure is reached or exceeded. It does not move a distance that is proportional for pressure. Mark, you can verify this action by applying pressure to the now open switch. I bet when it reaches ~120 psi, the plunger will suddenly move out.