SERVOPRO safe area

The digital controller platform for the AquaXact 1688 moisture sensor

Built specifically to work in harmony with the AquaXact 1688 ultra-thin film Aluminum Oxide moisture transmitter, this digital controller provides a high-clarity color touchscreen display, alarms, relays and advanced communications protocols, and allows easy sensor tip replacement in the field.

Seamless integration with the AquaXact 1688

Designed specifically to work seamlessly with the AquaXact 1688, this digital controller provides a high-clarity color touchscreen display, alarms, relays and advanced communications protocols.

It gives AquaXact 1688 users access to powerful, intuitive software control, and allows easy sensor replacement in the field. The sensor tip can be replaced by the user and the calibration file loaded into the transmitter via the digital controller, removing the need for return-to-factory calibrations and thus lowering costs of ownership.

Doug Barth
Douglas Barth
Senior Global Product Manager
Man with Servomex System components

Get the systems expertise you need

If you’re building a gas analysis system for your process, contact us. We have the experience and knowledge to ensure you get the solution you need, with project management from start to finish and state-of-the-art engineering. Contact us today.

Ready to buy? Here’s how it works

It’s easy to find the product you need for your application with Servomex

Servomex UK technical center


Get in touch to tell us what you need and the application you plan to use it for

Servomex Gas System Schematics


Our expert team will help you select the right product package, ensuring you have the accessories and support to get the best performance from your analyzer

Woman Assembling Sensors


Your analyzer will be assembled in one of our state-of-the-art engineering centers and rapidly dispatched to your site

The benefits of a digital controller

The AquaXact 1688 Controller is easy to connect to your moisture sensor for optimum control and added features.

A dedicated controller

Designed from the outset to work seamlessly with the AquaXact 1688, this digital controller provides all the display, alarm and communications options you’ll need.

Advanced communications

The controller offers Modbus, Ethernet Modbus TCP/IP and PROFIBUS communications protocols for reliable remote connectivity.

Compact footprint

The AquaXact 1688 Controller is easy to integrate into your system without taking up valuable space.


  • RS232 and RS484 digital outputs
  • Advanced digital communications including Modbus, Ethernet Modbus TCP/IP and PROFIBUS
  • Up to eight alarms and relays
  • Ability to digitally reset the range of the AquaXact probe for use as a 4-20mA power loop output device
  • Digitally access the AquaXact probe diagnostics in the field


Easy to use

  • Compact footprint for easy integration into your system
  • Advanced touchscreen GUI allows intuitive hands-on setup and operation
  • Bright colour touch screen display
  • Battery power option available for easy field tip replacements


Low cost of ownership

  • Minimal training requirements
  • Allows in-the-field calibration of replacement AquaXact 1688 sensor tips, eliminating costs of returning the transmitter to the factory


Unrivalled performance

  • Manufactured by Servomex to the same high standards as the company’s innovative gas analyzers
  • Seamless integration with the AquaXact 1688 moisture transmitter for advanced digital control of dew point and ppmV H2O measurements


Benchmark compliance

  • Complies with Low Voltage, EMC and applicable directives

Gases sensed, measurements and technologies

The AquaXact 1688 Controller is a digital platform designed for easy operation of the AquaXact 1688 moisture measurement sensor.

Gas Measurement
Water vapour (Moisture) (H₂O)dp, ppmv


SERVOPRO AquaXact Controller


  • IEC 61010-1
  • Overvoltage Category II, Pollution Degree 2
  • EU EMC Directive
  • EU Low Voltage Directive

Schematics (select to expand)


Dimensions of case 14 cm (H) x 20.5 cm (W) x 23 cm (D)


3200 grams

Get the detailed specifications

“For in-depth specifications you’ll want to download our technical datasheet which includes information on technology, performance, operating environment, sample conditions and compliance along with technical drawings and top-level benefits and applications.”

Doug Barth
Douglas Barth
Senior Global Product Manager

Download the complete resource pack

“Find out everything you need to know about the AquaXact 1688 moisture sensor and its digital controller. Our resource pack contains full details including features, benefits and technical specifications, and is available as a single download.”

Doug Barth
Douglas Barth
Senior Global Product Manager

Manuals and brochures

Download the operator manual and product brochure for the AquaXact 1688 Controller to discover more information, including set-up and maintenance information.

AquaXact 1688 Controller brochure

AquaXact 1688 Controller brochure

See for yourself

Our videos give you the chance to watch our products in action and hear from our experts. You can also see our analyzers unboxed, and find out more about our solutions for key applications

Unboxed: AquaXact 1688 & Controller

Applications Manager Chris Davis unpackages this moisture solution

Typical applications

The AquaXact 1688 Controller supports operation of the moisture sensor for a wide variety of gas phase process applications.

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

Air separation units

Diverse sensing solutions that adapt to your process

Learn more

Ethylene production

We have the solutions to make your process more efficient

Learn more

Medical gases

An advanced solution for purity assay and impurity detection

Learn more

UHP Gases / Semiconductors

A comprehensive systems solution

Learn more

Process heaters and furnaces

A choice of technologies to fit your application

Learn more

© Copyright 2022 - Servomex is a Spectris company.
Click here to download your selected documents