The differential pressure transducer monitors the differential pressure (pressure drop) between a point immediately upstream and a point immediately downstream of the full flow fuel monitor, water coalescer, or other device typically applied in aviation fueling systems. The maximum differential pressure is observed during the fuel delivery is electronically input into the LectroCount® LCR-ll® Electronic Register. The highest differential pressures reached during the delivery is printed on the delivery ticked to provide a record of the maximum pressure drop. The corresponding flow rate at which this maximum differential pressure is observed is printed immediately after the differential pressure reading.