Digital Microwave Sensors for Reliable, Accurate Moisture Measurement

Hydronix manufactures a range of microwave moisture measurement sensors which provide the ability to accurately measure moisture in most process control applications where the material is free flowing. The sensors use the contact method of measurement, where the material flows across the ceramic faceplate during processing. This enables them to take readings in real time of a consistent, representative material sample. All Hydronix sensors use unique digital technology ensuring that they can easily connect to a third party control system without any intermediary units.

Originally developed for use in the concrete and aggregates industry, Hydronix digital microwave sensors are used across a diverse range of applications which use mixers, blenders and conveyors during their processing and where accurate moisture levels are critical to the consistency and quality of the finished product.

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Moisture Measurement in Concrete Mixing

Hydronix sensors were originally designed for moisture measurement in concrete production, and are built to survive the harsh environment of flowing aggregates and the turbulence of a concrete mixer. Manufacturers need to produce quality concrete to a rigorous specification, batch after batch while keeping costs to a minimum.

  • Consistent batch quality
  • Consistent batch sizes when using the Hydro-Probe
  • Alarm function for high or low moisture contents
  • Reduction in cement use
  • Reduction in wastage due to incorrect moisture or slump
  • Reduced mix cycle times

One of the major problems of inconsistency in batching concrete is the ever varying moisture content of the sand and aggregates from one batch to another. Good storage of the sand and aggregates can help, but even for materials stored in covered silos the moisture will be forever changing due the inevitable effects of drainage. Moisture content in stored sand and aggregates can have dramatic effects on the water/cement ratio, the aggregate/cement ratio, yield and the colour of the mix. Measuring the moisture content of the raw materials can enable the plant controller to adjust water addition into his mix in real time, minimising these effects. This enables batch after batch of concrete to be produced to the same, consistent quality.

Moisture Measurement in Aggregates and Sand

  • Ability to batch the correct weight of sand regardless of water content
  • Reduction in number of spoiled batches
  • Ability to set alarm for high moisture levels

Modern plants can weigh aggregates with an accuracy of up to ± 0.5%. If the amount of moisture in a batch of sand or aggregates varies from between 2% to 10% then this will affect the accuracy and proportions of the weighed materials. Water is effectively being weighed and not dry materials.


Moisture Control in Asphalt Production

With increasing costs in raw materials, asphalt manufacturers are looking at ways to reduce costs while continuing to produce a consistent quality product. On-line moisture measurement in asphalt production is a cost effective method of reducing costs without affecting quality.

  • Reduce costs by maximizing output and more efficient use of materials
  • Monitor and ensure the efficiency of burners
  • Improve quality, by ensuring consistent gradation of aggregates
  • Reduce cost of poor quality by reducing the amount of remedial action/rework

Finer materials "hold" more moisture than coarser materials and increased moisture levels from factors such as rain will affect their weight. For manufacturers that grade by weight, this will lead to an incorrect ratio of combined materials. Without moisture control, the relative proportion of the finer materials will fall. This causes a reduction in density which will affect the quality of the finished product.

Measuring Moisture in Grain, Nuts, and Animal Feed Manufacturing

Controlling moisture in grain, nuts and animal feed throughout different stages of processing can be one of the biggest problems for manufacturers. All sorts of factors will affect the moisture level in the raw product; how it is stored, humidity in the atmosphere, the variety of the grain and also its particle size. All of these will have a contributing factor towards the amount of moisture that either needs to be added or evaporated during processing.

  • Reduction in energy costs as the correct of energy required for drying can be accurately calculated
  • Reduction in amount of wasted materials
  • Consistent, repeatable quality for end product

Correct moisture control will automatically lead to a reduction in spoiled material as the grain, nuts or animal feed can be processed using optimum liquid levels. Moisture measurement will provide an easy method to assist the producer in calculating the correct moisture input required. Microwave sensors are not affected by dust and vapor and have proved easy to use, reliable, accurate and cost effective.



Hydro-Probe II Moisture Sensor for Bins, Chutes, and Conveyor Belts

Digital sensor for accurate measurement of moisture in flowing materials such as concrete, sand and aggregates in bins, chutes or conveyor belts.

The Hydro-Probe II (HP02) was the first moisture sensor to use the digital microwave moisture measurement technique. It has integral signal processing which provides a linear output (both digital and analogue) and it can easily be connected to any control system. Typical applications include sand, cement, concrete, asphalt and aggregates, but the Hydro-Probe II has also been successfully installed in processing plants for grain, cereal, animal feed and aqua feed.

Designed for use in processing plants which use bins (silos), chutes and conveyor or feed belts, the sensor is positioned into the flow of material. Measurements are taken 25 times per second as the material passes over or around the sensor head, meaning that the sensor can rapidly detect changes in moisture levels. Real time adjustments to the moisture content of the material can then be made during processing if required. This ensures that the manufacturer can continually produce a consistent, quality product and reduce costs by limiting the amount of wasted or spoilt materials.

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Hydro-Probe Orbiter Moisture Sensor for Rotating Pan, Static & Plantetary Mixers

The World's first rotating microwave sensor for measurement of moisture and temperature in rotating pan, static and planetary mixers.

Originally supplied to the concrete industry, the Hydro-Probe Orbiter can also be mounted as a static sensor underneath a bin or above a belt conveyor and is therefore easily adaptable for use in other industries such as sand, aggregates, cereal, animal feed and fish meal.

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Hydro-Mix VI For Moisture Measurement in Mixers

Tough, digital, flush mounted sensor for measurement of moisture in wet and dry materials during the mixing cycle, in chutes and mixers.

Typically used to measure moisture in concrete mixing, the Hydro-Mix VI is also used successfully in other industries where it can be installed in a mixer, for example, grain processing and animal feed. The Hydro-Mix is fitted into the floor of a mixer or screw conveyor and takes measurements as the material flows over the ceramic head during processing.

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Communications & Network Adapters

Ethernet Adapter

Easily communicate with Hydronix sensors and controls via an Ethernet connection.

The Ethernet Adapter Kit is designed to provide a simple method for connecting Hydronix moisture sensors and controls. It reduces the need for customers to have expensive cabling and also provides sensor configuration and diagnostic functions across a remote connection. The unit is a small DIN rail mounted module which is compatible with networks using DHCP or fixed IP addresses. It would typically be located in a junction box near to the sensors.

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USB Sensor Interface Module

A simple method of interfacing Hydronix sensors to a PC or laptop for troubleshooting, testing and moisture display.

Water Control Systems

Hydro-Control V (HC05)

Simple to use, accurate water control unit for use with the Hydro-Mix for manual or automated batch plants.

The Hydro-Control V is a water control system from Hydronix. It is used in the concrete industry for controlling the mix cycle to automatically provide the correct addition of water in the shortest possible mixing time.

Using the reading from a Hydro-Mix or Hydro-Probe Orbiter sensor installed inside a mixer, the Hydro-Control V (HC05) accurately monitors the moisture levels of the material throughout the mix cycle, in both wet and dry mix stages. Using known recipes, the correct amount of water is then automatically calculated and added to the mix. This ensures that the required moisture target can be easily achieved, batch after batch.

Designed to be simple to operate and install, the Hydro-Control V can be used as a stand alone unit or installed into a control system, in both new and existing concrete plants. It has an easy to read graphical display which provides a wide range of information via a series of menus including mixing cycle status, recipe information, sensor signal trend and system diagnostics.



The main software utility used to configure, maintain and calibrate Hydronix microwave moisture sensors. The software may also be used for diagnostic purposes and upgrading sensor firmware.

A unique advantage of Hydronix sensors is the identical setup and configuration of each sensor when it leaves the factory. This allows quick and easy calibration of multiple sensors (or a replacement sensor) using Hydro-Com over an RS485 network or simply with a PC and USB or Ethernet connection.

Moisture Monitor


Monitor that displays both instantaneous and batch average moisture content readings from sensors.

For more information or to receive a quotation on Moisture Control Systems, click here