Processing Magazine

Economical two-wire, loop-powered output transmitter

February 9, 2009
New, low-cost loop-powered differential pressure and flow transmitters feature two-wire output. The transmitters are offered with or without a dial. The optional dial gauge is convenient when local or redundant readout of pressure or flow is desired. Loop-powered transmitters with two-wire, 4-20 mA output offer the advantage of user savings in installation. The transmitters are also offered with a standard three- or four-wire, 0-5 VDC output. The input voltage range for all configurations is 9-35 VDC. The transmitters have 2% FS accuracy and are built on the same pressure body as the manufacturer’s high line pressure (to 5,000 psi) gauges and switches. Users can select from many differential pressure ranges (0-5" H2O to 0-1000 psid) and flow ranges (0-1 GPM to 0-10 GPM). Built for environmentally harsh industrial applications, the transmitter electronics are protected by a durable, weatherproof enclosure with Class 1, Div. 1 & 2, Nema 4X and IP65 ratings. A 7/8" knockout is standard for 1/2" conduit connections.