The ATEX approved Series AT2DH3 Digihelic® Differential Pressure Controller is a 3-in-1 instrument possessing a digital display gage, control relay switches, and a transmitter with current output. Combining these three features allows the reduction of several instruments with one product, saving inventory, installation time and money. The ATEX approved Digihelic® controller is the ideal instrument for hazardous area pressure, velocity and flow applications by allowing for the selection of pressure, velocity or volumetric flow operation in several commonly used engineering units. Two SPDT control relays with adjustable dead bands are provided along with a scalable 4 to 20 mA process output. In velocity or flow modes, a square root output is provided on the 4 to 20 mA signal to coincide with the actual flow curve. Flame-proof ATEX enclosures are available in aluminum and can include a glass window for viewing process information and set point status on digital display. Important notes for installation: ? Cables must be fitted through 1/2" NPT cable glａnd or ATEX conduit (not supplied with instrument). ? Make sure after cabling to close tight cover and cable gland, in order to keep IP66 rating (IP65 with option OPV, overpressure relief valve). ? Open cover only after de-energizing instrument. ? Attention: Check local safety rules and warnings on unit and manual for a correct use of the instrument in hazardous area.Please see SERIES DH3 for non-ATEX approved.California Residents: Click Here for Proposition 65 WARNING.