Series 677 Differential Pressure Transmitters are designed to measure pressures as low as 0.1" w.c. with ±0.4% accuracy. Use Series 677 for building energy management systems, environmental pollution control, oven pressurization, lab and fume hood control, HVAC and VAV applications. The transmitter features 10 psid overpressure, reverse polarity protection and EMI/RFI protection. Internal regulation permits use with unregulated DC power supplies.