COMET T3111 – 4-20mA Transmitter with External Cable Probe for Temperature, Humidity, and Dew Point

COMET T3111 – 4-20mA Transmitter with external cable probe for temperature –30 to +105 °C, humidity 0–100 %RH, dew point 

The COMET T3111 is a reliable 4-20mA transmitter with external cable probe for temperature, relative humidity, and dew point – a classic solution for industry, building automation, BMS systems, PLC integration, climate chambers, warehouses, drying systems, or process monitoring. With a galvanically isolated current output (4-20 mA) and high long-term stability, it is perfect for connection to PLCs, controllers, recorders, or remote systems – even over long distances without signal loss.

The external combined probe measures temperature from –30 to +105 °C (±0.4 °C) and humidity from 0 to 100 %RH (±2.5 %RH from 5–95 % at 23 °C). The dew point is calculated internally (±1.5 °C at T<25 °C and RH>30 %). In addition, all other humidity parameters are available: absolute humidity, specific humidity, mixing ratio, and specific enthalpy. The output is freely scalable – you define the measuring range and which parameter (T, RH, Tdp, etc.) is output via PC.

The robust IP65 housing (electronics) and IP40 sensor make the T3111 a reliable partner for indoor and outdoor use (–30 to +80 °C). The galvanic isolation protects against ground loops and interference. The probe is replaceable, stable over time, and available with a traceable calibration certificate (according to EN ISO/IEC 17025) – top quality for critical applications. Power supply 9–30 V DC – simple and flexible.

Why the COMET T3111 is the professional 4-20mA transmitter:

• Galvanically isolated 4-20mA output – interference-proof & PLC-compatible
• External 1 m cable probe – flexible for difficult measuring points
• 3-in-1: Temperature + Humidity + Dew point – all humidity parameters available
• High precision – Temp. ±0.4 °C | Humidity ±2.5 %RH | Dew point ±1.5 °C
• Free scaling – configurable via PC (parameter & range)
• IP65 electronics + IP40 probe – for indoor & outdoor use
• Wide power supply range – 9–30 V DC
• Long-term stable & maintenance-free – with calibration certificate

Technical data T3111:

• Temperature measuring range: –30 to +105 °C (±0.4 °C)
• Humidity: 0 to 100 %RH (±2.5 %RH from 5–95 % at 23 °C)
• Dew point: –60 to +80 °C (±1.5 °C at T<25 °C and RH>30 %)
• Output: 4-20 mA, galvanically isolated
• Resolution: 0.1 °C / 0.1 %RH
• Probe cable length: depending on selection
• Power supply: 9–30 V DC
• Operating temperature: –30 to +80 °C
• Protection class: IP65 (electronics), IP40 (probe)
• Dimensions: 88.5 × 145 × 39.5 mm; probe Ø 18 mm, length 88 mm
• Weight: approx. 210 g
• Warranty: 3 years

Perfectly suited for:

• Building automation & BMS systems
• PLC & control technology
• Warehouse & production halls
• Climate chambers & drying systems
• Food & pharmaceutical production
• Data centers & server rooms
• 4-20mA remote transmission over long distances
• Integration into existing analog systems

Installation & commissioning – done in minutes

Mount the device, connect power (9–30 V DC) and the 4-20mA loop, place the probe at the desired location – done! Configure output via PC (COMET software): select parameter and range. No calibration required when replacing probe.

Available variants:

• Cable length 1 meter
• Cable length 2 meters
• Cable length 4 meters

Summary:

• Humidity and temperature transmitter
• For indoor and outdoor use
• Sensors for relative humidity and temperature in the probe on the cable
• Measured values are also converted into other humidity parameters: dew point temperature, absolute humidity, specific humidity, mixing ratio, specific enthalpy.

Scope of delivery:

• T3111 – cable length depending on selection above
• User manual
• Traceable calibration certificate
• Free TSensor software for transmitter configuration