The Digital draft gauge 4475-PX accepts the draft pressure input as the signal and displays it in terms of mmwc. It also delivers 4 -20 mA output proportional to the Draft. The Draft transmitter is a field mounting unit and is a two wire system delivering 4-20mA output proportional to Draft Input.The Transmitter can be mounted in the field thereby avoiding long lengths of impulse lines and also errors due to the lengths.Principal Features :Digital Display (so No Confusion)Much Better Accuracy compared to Mechanical Gauges.Wide Range of Draft measurement possible.Typically, 50 mmwc to 750 mmwc.Transmitter being Field Mounted, Errors due to Long Impulse lines are avoided.