A customer of ours wanted to pressurize an air line for a specific time.   Rather than rely on the operator to push a timer button, our customer wanted the timing to start automatically.  The idea was to utilize our T6 factory timer by connecting it to a pressure switch. The one they chose is made by Prosense model MPS25-1C-P200A

OPERATING SEQUENCE

• The operator manually pressurizes the air line.
• The timer starts a countdown cycle in response to the air pressure.
• At the end of the cycle the timer alarm activates. 
• The operator de-pressurizes the air line manually.
• The decrease in pressure stopps the alarm and the timer resets for the next cycle.

The T6 timer accepts either an NPN output from the sensor, or a contact close on the terminals marked MSw.  The timer needs a sustained contact close.  In this case of the ProSense pressure switch we did not use the powered 12V output, but instead we just connected the contact close coming from the mechanical switch.