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Appendix B: Introduction to 4-20 mA Current
AirLink 7032 Gas Monitor Operator’s Manual
Measuring Current
If the value measured is 0 mA, then: the loop wires are broken, the sensor assembly is not
powered up, the sensor assembly is malfunctioning, or the controller is malfunctioning. A digital
multi-meter (DMM), or current meter, may be used in conjunction with the controller and/or to
test the 4-20 mA current loop signal. To measure the current, place the meter probes in line with
the current loop.