The Flow Scanner – a complete measurement solution for wood chips in large industrial quantities.

Flow scanner © ANDRITZ


The Flow Scanner is the only instrument built to accurately measure key parameters of all the raw material used in large industrial processes such as pulp and paper and bio-energy.

Industrial design

The Flow Scanner is installed around the conveyor belt with 100 % of the wood chips passing through the machine. Its rugged design makes it run day in and day out, even in harsh environments with dust and varying temperatures.

Data integration

Data from the Flow Scanner can be directly integrated into your digester control system, making effective feed-forward control possible.


Better process control

Beforehand knowledge of the raw material means improvements in yield, productivity, energy, stability and quality in industrial processes such as pulp and paper and bio-energy production.


Know what you’re buying

Let the Flow scanner inspect every piece of material and provide a report on the full delivery, so you pay only for the material your process needs.


Find the rocks

Metals, stones, sand, glass, and other scrap items are just waiting for the opportunity to wreak havoc with your process. The Flow scanner scrutinises everything and makes an automatic removal system possible.


It measures water. But that’s not all.

The dual X-ray technique can reveal a lot more information about the organic material on the belt as well as the belt itself. Together with additional complementary techniques the Flow scanner can deliver a range of measurement data.



Moisture | Whether it is inherent to the material or free water, snow, or ice, the Flow scanner delivers this fundamental organic property with high accuracy, in an instant.


Weight icon

Weight | The Flow scanners two X-ray energy sources, measuring across the full width of the belt and with a tachometer, deliver wet mass flow rates. Together with the moisture measurement the amount of bone dry material in the process can be determined.


Foreign objects icon

Foreign objects | Inorganic material produces a very different signal on the X-ray detectors. The strength and area the signal covers can be set so that larger objects trigger an alarm for removal whilst smaller items are recorded only for review purposes.

Density icon

Bulk density | Does bulk density changes disturb your process? Sometimes its good to know when and why bulk density changes. Through the addition of optional line profile hardware the Flow Scanner can deliver volume and bulk density values.


Energy icon

Energy content | Energy production can be so much more efficient and cost effective if the bio-material is burnt correctly. On-line real-time analysis enables the power station to run with a constant energy content flow to reduce noxious gases and excess steam production.

Coming soon!

Volume icon

Volume flow | Limiting changes in volume flow are also a factor in a stable pulp production process. The Flow Scanner can give early warning of large changes and help route cause analysis.

Coming soon!


The Flow Scanner is directly calibrated against the only accepted moisture analysis method – gravimetric (oven) method. Similarly, mass flow data is calibrated against known samples during installation. The result is unrivaled measurement accuracy in both.

Note: MAE – Mean Absolute Error. The average error taken over at least 10 samples.


Range 30 – 65 %. Calibration samples are taken according to the SCAN method. If we take into account the error inherent with this reference process the Flow Scanner itself has an exceptionally low error.


Belt scales are notoriously difficult to maintain and accuracy is varied. A relief to know that the Flow Scanner has exceptionally high that is maintained without regular re-calibrations. A yearly test is recommended but experience from current installation sites shows insignificant loss of accuracy over long periods. 

Dry Weight

The result of the total weight (wet weight) measurement multiplied by the moisture content measurement. The high accuracy in both these signals gives the highest possible accuracy for this critical input. The error is low enough to be able to trust the on-line data and integrate it directly into the Digester Control System for automatic cooking liquor control. Contact Mantex for specific accuracy specifications with regard to your material and site conditions.

Foreign object detection

The Flow scanner detects just about all objects with a high density. Minimum specified sizes for alarm generation are 50 x 50 x 50 mm for metal objects and 70 x 70 x 70mm for rocks with >95 % confidence factor. Alarm signalled within 2 seconds of detection. Other sizes are recorded for statistical trace analysis.

Large range of material profiles

Almost any organic material can be scanned by the Flow Scanner. Materials are first analysed at the Mantex laboratory and a material profile constructed. The attenuation of the material at the different energies is recorded and loaded into the Flow Scanner analysis software. Signals from the detectors are processed with algorithms based on the material properties.



Choose from the list of existing material profiles or contact Mantex to discuss your process material and making new material profiles.Material profiles can be a single species or a mixture of several different ones. 

More about materials



The power of QDXA technology

Quantfiable Dual X-ray technolog is ideally suited to measuring organic material. X-rays pass through the entire material to be measured without damaging it in any way. Dual energy means the quantity of moisture can be determined even if the volume changes, dry content varies, and bulk density differs. 


Great accuracy

The Flow scanner is calibrated against the industry accepted standard suitable for the application – for example the gravimetric (oven) method. An instrument error of less than 1% is specified and is often significantly better.

100 % material

X-rays cover the full width of the belt and record every 1-2 mm as the chips are transported. This ensures all material is measured and eliminates the error from samples that are not representative of the whole flow.

Real-time results

Should your process require an instantaneous control signal or a rolling hourly average the Flow scanner delivers on-line data in real-time.


Snow and ice or hot and steamy, the Flow Scanner handles organic materials in any state. Frozen raw material with or without additional ice or snow.


Built for high-volume industrial use

The Flow scanner is built for demanding industrial applications. A sturdy splashproof outer frame is easily modified to be compatible with many different conveyor belt geometries and temperature environments. Overpressurised compartments and automatic pressurised air cleaning systems keep critical components dust free.


The Flow scanner is built to provide continuous round-the-clock performance without regular calibrations or cleaning, and with minimum maintenance. The availability is guaranteed better than 97% and is normally over 99%. 

Web enabled

Ethernet connection enables Mantex to monitor your Flow scanner status. This has proved invaluable for education, operational questions, advising and scheduling preventive maintenance.

Plugs into your control system

A choice of industry interfaces such as Profibus, and access to industry expertise, ensures effective integration to fully optimise your process.

Safety first

Although relatively low powered X-rays are used the safety of personnel is paramount. Installations all comply with local and international legislation and feature fail-safe interlock mechanisms, clear information, and customer training. In operation there are no special procedures that mill staff need to observe and can continue their work as before. When switched off there are no X-rays present and any maintenance work can be completed unhindered.


Maintenance engineers and lab personnel will be glad to hear that the Flow scanner features a monitoring system that automatically adjusts for belt wear-and-tear, temperature, and source variations.


The Flow Scanner is installed at a number of pulp mills and has been in operation for many years in the Nordic and Central European region. Contact us for references and a site visit.

Easy to install. Easier to maintain.

Mantex engineers have a simple three point plan for new installations that ensures a successful project.


Flexible installation

Engineers visit your site to detail the preparation work and Flow scanner modifications required. Help is even available, together with external consultants in the industry, to complete the Benefit analysis, and an optimisation study so the Flow scanner has the maximum effect.

Short downtime

The Flow scanner tunnel is erected with minimum disruption to production. The rest of the instrument can then be assembled in safety with only a short stop to insert the detector and perform switch on, testing, and calibration.

Low maintenance

The system is handed over for customer validation and integration. Regular weekly maintenance is light and Mantex engineers are on-hand to assist operations throughout the support phase.