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COMET H3331 – Temperature and Humidity Controller with Remote Probe

COMET H3331 Temperature & Humidity Controller RS232     

The COMET H3331 is a powerful temperature and humidity controller with a remote probe on a 1-meter cable – ideal for applications where the electronics must remain outside the measuring zone or where extreme environmental conditions prevail. The high-quality combined probe measures accurately up to +105 °C and 100% relative humidity, ensuring reliable use in drying chambers, climate cabinets, ripening systems, greenhouses, or demanding industrial environments.

Two potential-free relay outputs (2 A / 50 V) directly control heaters, coolers, humidifiers, dehumidifiers, or fans. Thanks to the integrated dew point calculation, control can be based directly on the dew point – ideal for preventing condensation in cold rooms or optimizing processes in food and pharmaceutical production. If a value exceeds preset limits, a loud acoustic alarm sounds for maximum safety.

The RS232 interface makes the H3331 an ideal component for modern control and monitoring systems. Three binary inputs allow the connection of door/window contacts, external switches, or safety circuits. Configuration takes only a few minutes using the free TSensor software.

The robust IP65 enclosure and remote probe (IP40) are built for continuous industrial use. Whether in dusty warehouses, damp basements, or hot drying processes, the H3331 provides stable readings and reliable switching for years.

Your advantages with the COMET H3331 at a glance:

  • Remote probe on a 1 m cable – electronics remain protected, probe up to +105 °C
  • 2 relay outputs (2 A / 50 V / 60 VA) – direct load switching
  • Control by temperature, humidity, or dew point – maximum flexibility
  • Acoustic alarm – instant local warning
  • 3 binary inputs for external signals (e.g. door open, emergency stop)
  • RS232 interface – easy integration
  • Highest accuracy: temperature ±0.4 °C, humidity ±2.5 %RH
  • Dew point accuracy ±1.5 °C – ideal for condensation protection
  • Rugged IP65 housing + 3-year warranty
  • Easy configuration via TSensor software

Detailed technical data:

  • Probe temperature 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 %)
  • Relays: 2 × potential-free, max. 50 V / 2 A / 60 VA
  • Binary inputs: 3 × dry contact / open collector (not galvanically isolated)
  • Probe cable length: 1 meter (optional 2 or 4 m)
  • Communication: RS232
  • Power supply: 9–30 V DC
  • Protection rating: enclosure IP65, probe IP40
  • Operating temperature: –30 to +80 °C
  • Warranty: 3 years

Perfectly suited for:

  • Drying and ripening chambers
  • Climate and incubator cabinets
  • Cold storage rooms (dew point control for condensation prevention)
  • Greenhouses and agriculture
  • Food and pharmaceutical production
  • Chemical processes and paint drying
  • Server rooms and data centers
  • Industrial furnaces and heat treatment

Installation – quick & safe

The housing is mounted on the wall with two screws, and the probe can be flexibly positioned where measurements are needed. Spring clamp terminals and clear labeling make wiring simple. The H3331 is ready for operation within minutes.

Summary:

  • Hygrostat with two relay outputs
  • For indoor and outdoor use
  • Measurement of relative humidity and temperature via cable probe
  • The measured values are converted into additional humidity parameters: dew point temperature, absolute humidity, specific humidity, mixing ratio, and specific enthalpy
  • Three binary inputs
  • The device is supplied with a temperature and humidity (T+RH) probe with 1-meter cable

Scope of delivery:

  • H3331
  • User manual
  • Traceable calibration certificate
  • Free TSensor software for transmitter configuration
Datasheets
Datasheet 1

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Datasheet 1 (1.65 MB)
Datasheet 2

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Datasheet 2 (131.03 KB)

Temperature and Humidity Controller with RS232 Output

Measured values

  • Temperature
  • Relative humidity
  • Calculated values (dew point …)
  • Two-state signal

Temperature sensor

  • Measuring range: −30 to +105 °C
  • Accuracy: ±0.4 °C
  • Resolution: 0.1 °C

Humidity sensor

  • Measuring range: 0 to 100 %RH
  • Accuracy: ±2.5 %RH (from 5 to 95 % at 23 °C)
  • Resolution: 0.1 %RH

Dew point sensor

  • Measuring range: −60 to +80 °C
  • Accuracy: ±1.5 °C under ambient conditions T < 25 °C and RH > 30 %
  • Resolution: 0.1 °C

Relay outputs

  • Quantity: 2
  • Maximum voltage: 50 V
  • Maximum current: 2 A
  • Maximum power: 60 VA

Binary inputs

  • Quantity: 3
  • Signal: dry contact, open collector, or two-state voltage signal
  • Inputs not galvanically isolated
  • Minimum pulse duration: 500 ms
  • Voltage across open contact: < 3.3 V
  • Low level: 0 to +0.5 V
  • High level: +3.0 to +30 V

General technical data

  • Operating temperature: −30 to +80 °C
  • Number of channels: 1× connectable temperature and humidity probe
  • Calculated values: dew point, absolute humidity, specific humidity, mixing ratio, specific enthalpy
  • Acoustic alarm: integrated buzzer, switchable
  • Output: RS232
  • Humidity sensor temperature compensation: over the entire temperature range
  • Available temperature units: °C, °F
  • Communication protocols: ModBus RTU, Advantech ADAM (compatible)
  • Power supply: 9–30 V DC
  • Protection rating: IP65 electronics; IP40 sensors
  • Dimensions: 136 × 159 × 45 mm; length/diameter of external probe: 88 / 18 mm
  • External probe cable length: 1 m
  • Weight: approx. 500 g
  • Warranty: 3 years

Manufacturer Information:

COMET SYSTEM, s.r.o.

Bezručova 2901

756 61 Rožnov pod Radhoštěm
Czech Republic

Phone: +420 571 653 990

Email: info@cometsystem.com

Responsible person:

Didactum® Security GmbH

Marsweg 17

48163 Münster
Deutschland

Fon: +49 - 2501 - 9 78 58 80

Email: info@didactum-security.de

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