AquaXact 1688

A fast, accurate and resilient moisture measurement solution for a range of gas phase process applications


Sensing Technology


The AquaXact 1688 is a rugged, ultra-thin film Aluminum Oxide moisture sensor that enables fast and accurate dew point and ppm H2O measurements of moisture in a wide variety of gas phase process applications.

Not only is it a standalone 4-20mA transmitter, but it is also able to be remotely interfaced to the SERVOPRO MonoExact DF310E, SERVOPRO MultiExact 4100 and the AquaXact 1688 digital controller. The controller provides a high-clarity color touchscreen display, alarms, relays and advanced communication protocols including RS485, Modus RDU, Modbus TCP/IP and PROFIBUS. Optional internal oxygen sensors provide ppm to percent level O2 measurement capabilities.

The Al2O3 thin film sensor tip can be replaced by the user and the associated calibration file loaded into the transmitter using the controller, eliminating the need for return-to-factory calibrations. Yearly field calibration adjustments require only a single gas standard.

The sensor element is NIST-traceable and field-replaceable, for hassle-free recalibration.

Stainless steel, weatherproof casing (Class 1 Division 2 in 2019) enables operation in ambient temperatures ranging from -10°C to +70°C.

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  • Air Separation Units
  • Natural Gas Processing and Transportation
  • Glove Boxes
  • Instrument Air Units
  • Ethylene Production
  • Refining Gases
  • Medical Gases
  • Semiconductors
  • Furnace Gas/Heat Treating
  • Power Generation
  • Air Dryers
  • Pharmaceutical
  • Aerospace



Ensure your AquaXact 1688 moisture sensor delivers optimum performance with Servomex Service Network.

Through our global network of engineers and service centers, we provide complete lifetime support for your analyzer. Our services range from installation and commissioning to supplying high quality spares and arranging scheduled servicing: visit our Service Network pages to find out more.