Features, Sand Processing

Moisture measurement of sand in cement production

Port Hedland

Manually managing the moisture measurement in the laboratory can be a slow process.

However, installing a sensor for continuous moisture measurement can be just the solution.

To produce cement, a German manufacturer required sand taken either from internal storage facilities or delivered by ship. 

It found that the material had a much higher moisture level when it was transferred across the water.

The company previously checked the material moisture manually in the laboratory, but this was a slow process. 

It was therefore looking for a continuous moisture monitoring system for the sand transportation.

To solve this issue, the company installed SWR Engineering’s M-Sens 3, a microwave sensor specifically designed for continuous moisture measurement of solids during batching. 

The sensor monitors product flow for its moisture content and temperature, which can be used to detect the efficiency of the product stream. 

Dusts, powders, granulate and other bulk solids are constantly analysed to identify process failures, such as a defective screw or material clogging.

The M-Sens 3 sensor functionality is based on precise high-frequency measurement and direct digitalisation of measured values, which results in a high resolution. 

The use of up to three sensors, connected to a MSE 300 evaluation unit, means induced measurement inaccuracies caused by the materials inhomogeneity can be reduced. 

The influence of bulk density variations, which normally exist over the whole measurement zone, are also reduced by an internal filter function.

The sensor does this by monitoring the material’s surface and capillary moisture, which influences the specific conductive capacity of a material. 

This can then be compared to a averaged bulk density to determine if investigation is required.

In the event of a material process failure or caking around the sensor, an alarm can be sounded to ensure the validity of the measurements is always high.

Temperature variations are also compensated automatically by the sensor.

The temperature measurement is calibrated in-factory and doesn’t need any additional operation from use. 


The German cement manufacturer installed the M-Sens 3 directly on the conveyor belt with a shuttle to continuously monitor the moisture content of the sand.

The work required to take samples and check moisture levels in the laboratory is no longer necessary, saving time and costs.

On a conveyor belt system, the M-Sens 3 can measure moisture of the solids and allow operators to react in real-time if material is too humid or dry, helping prevent plugging of aggregates.

Additionally, when mounted at a bin’s outlet, the sensor can take advantage of the constant bulk density and almost unchanging measuring field for monitoring residual moisture.

This helps operators stop material that is too damp from reaching the next production level.

The system itself has been designed for easy installation and calibration. 

All an operator needs to do to calibrate the sensor is press a button and enter the referenced moisture content. 

Measured fluctuations in bulk density and temperature are automatically compensated by an internal filter function. •

Visit bintech.com.au for more information.

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