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testo 6681 - Temperature and humidity transmitter for critical applications

0555 6681
  • Maximum measuring accuracy thanks to reliable and long-term stable humidity sensor technology
  • Ethernet, relay and analog outputs enable optimum integration into individual automation systems
  • Suitable special probes for high-humidity and trace humidity applications and aggressive media
  • Robust, easy-to-clean metal housing
  • The testo 6681 temperature and humidity transmitter is designed for monitoring critical climate in industrial processes (e.g. production/process engineering). If these involve maximum precision or specialized applications (high humidity, trace humidity, etc.), then this climate transmitter is the ideal choice because, when it comes to humidity measurement, it features unrivalled cutting-edge technology.
    Industrial humidity measurement requires absolute professionalism in measuring and control technology. In industrial processes or in research-based business, the testo 6681 temperature and humidity transmitter is ideal wherever critical climatic values need to be maintained. The climate transmitter boasts a high-precision humidity sensor with long-term stability (optionally available), which enables it to achieve maximum precision: up to ±(1.0 + 0.007 * reading).

    Precise measuring and control technology will help you to accurately optimize the climatic conditions in your rooms in order to prevent process disruptions and quality losses. Automation systems result in particularly efficient processes. The testo 6681 temperature and humidity transmitter can easily be integrated into individual automation systems because it features Ethernet, relay and analog outputs.

    Areas of application for the testo 6681 temperature and humidity transmitter

    -  Drying processes (e.g. drying tobacco, manufacturing ceramics, drying roofing tiles)
    -  Painting installations
    -  Food production (e.g. cheese processing, ripening fruit, drying pasta)
    -  Bio-research
    -  Breeding mushrooms
    -  High-humidity specialist fields
    -  Sterilization processes in an H2O2 environment
    -  Clean rooms
    -  Museums
    -  Storing hygroscopic substances
    -  Storing electronic components

    Technical highlights of the testo 6681 climate transmitter

    High-quality digital probes available for the temperature and humidity transmitter: e.g. high-precision Testo humidity sensor with long-term stability, probe for high-humidity measurement, probe for trace humidity measurement, probe with a self-monitoring function (for measuring in sensor-damaging media)
    Smart probe technology: probe can be changed by the user, digital interface for the temperature and humidity transmitter, intelligent calibration concept
    Ethernet, relay and analog outputs allow for versatile use of the temperature and humidity transmitter: e.g. for control purposes (2 or optionally 3 analog outputs), for direct activation of units in the air conditioning system (optionally via relay) or even in climate monitoring systems (optionally via Ethernet connection)
    P2A software for parametrization, adjustment and analysis saves time and money during commissioning and maintenance
    Optimum protection: the climate transmitter features a robust metal housing and is protected against water jets according to protection class IP 65. Protective caps are also optionally available for specific applications (made of stainless steel, PTFE, wire mesh filter or metal). A patented H2O2 protective cap is also available to order
    2-line display: the climate transmitter is optionally available with a display, enabling you to undertake commissioning, adjustment and analysis without using a PC
    Options for self-monitoring and early warning function: guarantees high system availability

    In combination with the right probe, the testo 6681 temperature and humidity transmitter offers superior properties and benefits in comparison with a conventional climate transmitter because, when it comes to temperature and humidity measurement, this instrument features supreme, cutting-edge technology.

    Note: Please note that the transmitter can only be operated with a probe. The probes are optionally available.

    testo 6681 temperature and humidity transmitter with selectable signal outputs, 2-line display (optional), Ethernet/Profibus module (optional), output of all relevant humidity variables, relay (optional), 3 analog outputs (optional).


  • Accessories
    Condensation protector made of aluminium
      0554 0166
    • Accessories
      P2A PC software
        0554 6020
      • Accessories
        Wall bracket / duct bracket
          0554 6651
        • Accessories
          Protective cap made of PTFE with drip hole
            0554 9913