Adjustable pots TR1 and TR2 have been pre-set for proper operation and further adjustment should be unnecessary.
TR1 sets the trip-point for the red ‘Over-Pressure’ alarm LED on the front of the unit. TR1 has been pre-set to light the red LED when the system pressure exceeds 15 lbs/sqr-inch. This increase in pressure to the 15 lbs/sqr-inch level could occur while attempting to quickly purge or pressurize a transmission line. Since the LED will light at a system pressure of 15 lbs/sqr-inch, this should be ample warning to either reduce system pressure or temporarily disconnect the sensor from the line while performing these high pressure operations.
TR2 sets the output zero-pressure reference voltage. It has been pre-set for zero(0) volts output at zero(0) pressure applied to the pressure port.
The DC voltage output of the sensor will vary linearly with the applied pressure and will provide approximately 4-4.5 VDC output with 15 lbs/sqr-inch applied to the pressure port.