Pacific Sensor Tech supplies 4-20mA output transmitters and sensors for accurate, reliable industrial monitoring. The 4-20mA current loop is the most widely used analogue signal standard in process control — it transmits a parameter over long cable runs with strong noise immunity, built-in fault detection (any reading below 4 mA flags a fault), and loop-powered two-wire simplicity. Our programmable COMET transmitters convert temperature, relative humidity, CO2, dew point and pressure into a stable 4-20mA signal for PLCs, dataloggers and SCADA systems.
Need a different output? See our 0-10 V output transmitters and Ethernet / Modbus transmitters, or browse all
sensors by measured value.
Pacific Sensor Tech supplies 4-20mA output transmitters and sensors for accurate, reliable industrial...
Temperature transmitter with 4-20mA output
…
Intrinsically safe humidity and temperature trans…
Intrinsically safe humidity and temperature trans…
Compressed air RH+T+Tdp sensor with 4-20mA output…
Temperature and humidity duct probe with 4-20mA o…
Intrinsically safe humidity and temperature duct …
Temperature and humidity bar type probe with 4-20…
Temperature sensor with 4-20mA output
Measu…
Relative Humidity probe with 4-20mA output
…
Barometric pressure transmitter with user adjusta…
Economy humidity and temperature transmitter with…
Temperature and humidity outdoor, indoor probe wi…
Humidity and Temperature transmitter with externa…
CO2 concentration transmitter with 4-2…
Measure temperature from -200 °C to +600 °C with RTD (Pt100/Pt1000) and thermocouple transmitters that output a linear 4-20mA signal. COMET programmable temperature transmitters let you scale the 4-20mA range to your exact span, making them ideal for HVAC, cold-chain, cleanroom and process applications. Browse our full temperature sensor range for probe and housing options.
Monitor relative humidity and temperature together with dual-output 4-20mA transmitters. Each channel delivers an independent 4-20mA signal, so a single device covers two measured values — perfect for storage, horticulture, museums and HVAC validation. Dew-point output is available on selected models.
Non-dispersive infrared (NDIR) CO2 transmitters with 4-20mA output for indoor air quality, greenhouse and ventilation control. Stable, drift-compensated readings across 0–2000 / 0–10000 ppm ranges.
Loop-powered 4-20mA pressure transmitters for gauge, absolute and differential pressure across industrial and HVAC duct applications, with selectable ranges and fast response.
Fault detection — any current below 4 mA indicates a broken wire or sensor fault, not a valid zero.
Long-distance integrity — current loops hold accuracy over hundreds of metres of cable.
Noise immunity — a current signal resists electrical interference far better than voltage.
Loop-powered simplicity — two wires carry both power and signal, lowering wiring cost.
A 4-20mA transmitter converts a physical measurement — temperature, humidity, CO2 or pressure — into a proportional electrical current between 4 and 20 milliamps. 4 mA represents the bottom of the measuring range and 20 mA the top, giving a simple, linear analogue signal that PLCs, dataloggers and SCADA systems read directly.
A current loop keeps its accuracy over long cable runs and resists electrical noise far better than a 0-10 V voltage signal, which drops over distance. The ‘live zero’ at 4 mA also enables fault detection: a reading of 0 mA means a broken wire, whereas 0 V is ambiguous. For short runs or multi-channel digital needs, see our 0-10 V and Ethernet transmitters.
A loop-powered, or two-wire, transmitter draws its power from the same 4-20mA loop that carries the signal, so only two wires are needed for both supply and measurement. This simplifies wiring and reduces installation cost.
Yes. Dual-parameter COMET transmitters provide two independent 4-20mA outputs — for example one for relative humidity and one for temperature (or dew point) — from a single device.
Most COMET transmitters are field-programmable: you can rescale the 4-20mA range to your required measuring span and configure alarms or filtering, so the same hardware fits many applications.
Any device with a 4-20mA analogue input — PLCs, RTUs, paperless recorders, dataloggers, indicators and SCADA I/O modules. The signal is an industry standard, so cross-brand compatibility is straightforward.
Yes. Pacific Sensor Tech ships 4-20mA transmitters and sensors Australia-wide, with local support and technical advice on selecting the right range and probe.
