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Comet Remote CO2 concentration thermometer hygrometer with Ethernet interface and two relays


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Comet Remote CO2 concentration thermometer hygrometer with Ethernet interface and two relays

Temperature, humidity, CO2 level sensor with two output relays.

Sensor H6520 is designed for online monitoring of temperature, relative humidity and CO2 of air without aggressive substances. Other devices are controlled by two relay outputs.

High precision capacitive polymer sensor ensures excellent long term calibration stability and ultimate accuracy. Measured values are also converted to other humidity interpretation: dew point temperature, absolute humidity, specific humidity, mixing ratio and specific enthalpy.

The CO2 measurement is based on a 2-source, 2-beam process. CO2 measurement with long-term stability is guaranteed thanks to the proven non-dispersive infrared (NDIR) CO2 measurement cell. The unique patented auto-calibration procedure compensates for aging of the infrared source and guarantees high reliability, long term stability and eliminates the need of periodical recalibration in the field.

The CO2 concentration is shown on the display or signaled by a color LED.



  • Temperature
  • Relative humidity
  • Counted values (dew point…)
  • CO2


  • Measuring range -30 to +80 °C
  • Accuracy ±0.4 °C
  • Resolution 0.1 °C


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


  • Measuring range -60 to +80 °C
  • Accuracy ±1.5 °C at ambient temperature T <25 °C and RH >30 %
  • Resolution 0.1 °C


  • Measuring range 0 to 2000 ppm
  • Accuracy ±(50ppm +2% from reading) at 25°C and 1013hPa
  • Resolution 1 ppm


  • Quantity 2
  • Maximal voltage 50 V
  • Maximal current 2 A
  • Maximal power 60 VA


      • Operating temperature -30 to +60 °C
      • Channels internal temperature, humidity and CO2 sensor
      • Counted values dew point, absolute humidity, specific humidity, mixing ratio, specific enthalpy
      • Acoustic alarm from built-in beeper - switchable
      • Output Ethernet
      • Measuring interval 2 s; CO2 15 s
      • Available temperature units degrees Celsius, degrees Fahrenheit
      • Communication protocol WWW, ModbusTCP, SNMPv1, SOAP, XML
      • Alarm protocols E-mail (SMTP authentication is supported), SNMP Trap, Syslog
      • Power 9-30 Vdc
      • Protection class IP30
      • Dimensions 136 x 213 x 45 mm; stem length 75mm
      • Weight approx. 340 g
      • Warranty 3 years


      * the features may vary depending on the device type

      • accurate measurement of Temperature, Relative humidity, Dew point, Atmospheric pressure, CO2, Two-state events
      • communication protocols SNMP, Modbus TCP, SOAP, XML
      • webserver to display current and recorded values
      • alarm indication via email
      • selected models with PoE
      • data analysis in COMET Database software


      Comet Database One Click Installer (20.1-II)

      Database Viewer dbapi 20.1

      TSensor (3-4-1-0)

      Sensor Reader (2-0-6-0)

      Conversions - application for recalculation of values


      Terms and Conditions COMET System s.r.o.


      Quick Start Manual

      Declaration of Conformity

      COMET Cloud security

      How to add WebSensor to COMET Cloud



      CATALOG - CO2

      CATALOG - WebSensors with Ethernet output and relay Catalog

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