ZD21 Transmitter

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For more than 60 years, GfG has been committed to protecting people, industrial facilities and the environment by developing and manufacturing gas detection systems. With an extensive range of portable gas detectors and fixed gas detection systems, GfG can supply you with a selection of products for many applications and industries. Our scope also includes on-site service and advanced training courses.


What distinguishes us from other manufacturers

We are specialists for gas detection solutions, not generalists in safety. No one can be the best at everything, but if you focus on one thing, you can achieve excellence. We work hard to provide you with the best gas detection equipment available, so you can focus on your task without having to worry about the risks that gases can pose. Because of that we invest more heavily in research and development than any other company. Approximately 13% of our annual turnover is reinvested in basic research and the development of new sensors and devices.


A “never say no” approach

This includes finding solutions for customers whose requirements are not met by “off the shelf” products. We take pride in our longstanding cooperation with the Singapore Civil Defence Force (SCDF), for example. For many years now, they have put their trust in GfG’s portable devices, which we optimized to adapt to the Singaporean climate and fulfill the special requirements for integration into the SCDF communication network.

The ZD21 is characterized by its high selectivity and long-term stability. Oxygen sensors with different measuring ranges are available. These range from very low concentrations (0 to 1000 pm) to high concentrations (0 to 96 vol.%).The sensor can also be installed remotely.  The maximum cable length between the transmitter and the external sensor is 2 meters.

Rugged and durable
The transmitter housing is made of aluminum. It is protected against dust and water ingress (IP54). The O2 sensors have a long sensor lifetime of 5 years and are insensitive to CO2. Temperatures between -30 and +50 °C, very low or very high humidity and extreme pressure do not affect the accuracy of the oxygen measurement.

Communication and service
Changes in the O2 concentration are detected within a very short time ((t90 > 2 s). The measurement signal is communicated analog to the controller (0.2-1 mA or 4-20 mA). A calibration adapter is available for the test gas supply during the regular function tests. The adjustment can be performed by a single technician.


Key features at a glance:

General information:

  • Measuring principle: Zirconium dioxide (ZD)
  • For oxygen
  • Optional remote sensor (maximum cable length: 2 m)
  • Short response time (t90 < 2 s)
  • Expected sensor lifetime: 5 years
  • Signal transmission: 0.2-1 mA or 4-20 mA
  • Protection class: IP54

Optionally available:

  • Flow adapter, remote calibration adapter, weatherproof housing

Would you like to know more?

Our team can help you with any product information, quotes, or any general questions you may have about the product.

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ZD21 Transmitter

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