WIKA A2G-52 Dual Differential Pressure Sensor for HVAC

The WIKA model A2G-52 combines two differential pressure sensors in a single instrument, so pressure can be measured at two separate control points at once. It is used with air and non-aggressive, non-flammable media, for fan, blower and filter monitoring, pressure and flow monitoring, monitoring and control of valves and air shutters, and pressure monitoring in clean rooms.

The measuring element is a piezo cell and the data sheet gives the measuring range as -250…+2,500 Pa and -250…+7,500 Pa. Accuracy on the -250…+2,500 Pa range is ±2 Pa + 1 % below 125 Pa and ±1 Pa + 1 % above it; on the upper range it is ±2 Pa + 1.5 % below 125 Pa and ±1 Pa + 1.5 % above. Measured values can be shown in Pa, mbar, inWC, mmWC or psi.

Output is Modbus RTU over RS-485 at 9,600, 19,200 or 38,400 baud with addresses 1…247, and a two-line LC display of 12 characters per line shows the active measurement at input A on the first line and input B on the second. Two further inputs accept passive temperature sensors — Pt1000, Ni1000, Ni1000-LG or NTC10k — or a 0…10 V analogue signal, so separate active temperature transmitters are not needed.

The process connection is a copper-alloy connecting nozzle, lower mount, for hoses of 4 mm inner diameter. Supply is AC 24 V or DC 24 V ±10 % through an M20 cable gland to two sets of four spring-clip terminals. The case is ABS with a polycarbonate cover, ingress protection IP54, ambient temperature -20…+70 °C, medium temperature -10…+50 °C and weight 150 g.