Pressure switches may be used on applications where an electrical signal is needed in the event that the pressure reaches a set pressure.  The may also be used where a machine will be shut off when the pressure drops below a set pressure.  These are generally low level signals coming from the pressure switch, so the correct rating in Amps for the pressure switch should be selected.  To quickly figure how many amps your circuit needs, use the following formula:   For DC Volts, V=I times R where V is Volts, I is Amps and R is Resistance.  Measure the resistance across the circuit that the switch will be supplying, then divide the Volts by the resistance that you measured and you have the Amps. (example 12 VDC/ 50 Ohms = .24 Amps).  If you exceed the amp rating on the switch, it will greatly diminish the service life. 

      The sensor switches are made to operate on cylinders that contain magnetic pistons.  Most cylinders are designed to accomodate certain switches.  The RCA type can be mounted on all tie rod cylindes with a mounting bracket that is also available.