4-20 mA


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4-20 mA

(4 to 20 MilliAmp) A point-to-point or multi-drop circuit mainly used in the process automation field to transmit signals from instruments and sensors in the field to a controller. It sends an analog signal from 4 to 20 mA that represents 0 to 100% of some process variable. As a current loop signal, 4-20 mA also powers the sensor transmitter on the same wire pair, and 4-20mA provides more resistance to interference than a voltage-based line. See HART.
References in periodicals archive ?
Over 60 analog and digital temperature meters include thermometers with stainless-steel and upright stems; panel-mount meters and transmitters with type J, K, T, and E thermocouple probes; strip-chart and circular temperature recorders; infrared meters for noncontact measurement (portable and remote models with 4-20 mA output); and multichannel, 4-20 mA or 0-5 VDC temperature monitors with alarm systems.
The 4-20 mA output makes the SMI-L suitable for geotechnical applications where long cable runs are required since there is no signal loss due to.
The product line includes pipe sizes ranging from 1/4 inch to 4 inches, providing 4-20 mA transmitter flow rates ranging from .
The SOLID line is a range of transducers, 4-20 mA transmitters and composite connectors designed and built to withstand tough environments under the most demanding conditions.
Millivolt, voltage, and 4-20 mA outputs available on standard products.
The fuel monitoring system consists of two JVKG positive displacement flow meters, one for the supply line and one for the return line; and an AW Company FEM-03A2 which will display flow rate and net fuel consumed plus a 4-20 mA output available for remote reporting, www.
The two-wire design utilizes 24 Vdc power with 4-20 mA output and is used as a direct interface with existing control and data acquisition systems.
A DIP switch on each unit allows the following selection of control inputs: 1-135 ohms, 4-20 mA, 0-5 V.
c it provides a 4-20 mA process output and two SPDT relays with adjustable dead bands.
It accepts regulated and unregulated excitation voltages, and provides output signals such as 1-5 VDC, 1-6 VDC, 4-20 mA, or a ratiometric 0.
The Water Reporter is a compact, programmable micro controller that supports up to 3, 4-20 mA analog inputs which can be uniquely identified.
4-20 ma, dc from plc to operate the valve output signal 4-20 ma from position transmitter atr supply 6 kg.