Dwyer DHC-004 Digihelic® Differential Pressure Controller is a high-accuracy device with an operating temperature range of -4 to 158°F (-20 to 70°C). It offers ±0.5% FSO accuracy for most ranges, except for 0.5 in w.c. @ ±1% FSO and ranges at or below ±0.25 in w.c. @ ±1.5% FSO. The controller can be powered by 12-28 VDC or 12-28 VAC 50 to 400 Hz and has a quick response time of 400 ms. It is encased in a NEMA 4X (IP66) rated enclosure and features a backlit LCD display with LED setpoint indicators. The device offers various output signal options and has zero and span adjustments accessible through menus. It is suitable for air and non-combustible compatible gases and can be mounted in any orientation. The controller is made of polycarbonate material and has 1/8" female NPT ports for process connections. It operates with a power consumption of 3 VA max and has two SPDT relays for switch type. Additional features include set point adjustment accessible through menus, thermal effect of .02% FS / °F (.036% FS / °C), and BACnet MS/TP or Modbus® RTU communication compatibility. The device dimensions are 5" OD (127 mm) x 1.9" (48 mm) deep, and it has a stability of < ±1% / year FSO.