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Technology – Electrical Tomography

Rocsole’s process imaging solutions are based on Industrial Process Tomography, more precisely Electrical Tomography (ET). Tomographic methods are typically used for imaging internal structures of targets that require non-invasive or non-destructive measurement techniques.

The general idea in tomographic measurements is to expose the target of interest to a physical stimulus, e.g. electromagnetic waves, radiation beam, acoustic waves or electrical signals, and measure the response caused by the target. From the response signals it is possible, with the aid of mathematical models, to infer the distribution of different material within the target.

An important feature of tomographic imaging techniques is that measurements can be conducted form outside the actual target without damaging or disturbing it.

Rocsole’s systems are developed to handle tough process conditions and contain no moving parts, so a regular service or maintenance program is not needed.

Sensor and control unit 15W, data cabinet 20W, connection unit 15W.

In electrical tomography techniques, such as Electrical Resistivity Tomography (ERT), Electrical Capacitance Tomography (ECT) and Electrical Impedance Tomography (EIT), known voltage or current is applied to the periphery of the target via an appropriate electrode configuration. This will induce an electrical potential distribution in the target, and the shape of the potential distribution depends on the distribution of materials within the target.

The effects of material distribution can be measured with the electrodes attached on the periphery of the target domain. With suitable mathematical models and data processing algorithms it is possible to determine images of material distributions in the region of interest.

In process industry, this information may be very useful e.g. for optimal process control. Main advantages of electrical tomographic techniques are good time resolution, affordable price and negligible health and safety issues. Check ET Technology page for more information about utilizing ET technology in industrial environments.

Industrial Process Tomography is a general term for techniques intended for cross sectional or 3D imaging of material properties and distributions in various industrial positions such as in pipes, vessels and reactors. Process tomography covers several tomographic techniques, e.g. electrical, X-ray and ultrasound methods, and typical applications include e.g. monitoring of different mixing and sedimentation processes as well as determination of material concentrations and distributions in multiphase flows.

An important feature of tomographic techniques is that the measurements are typically carried out from the periphery of the target using a specially designed sensor so that the measurements do not disturb the process. Tomographic measurements enable non-invasive process monitoring, which can give comprehensive understanding on the behavior of the process system and provide valuable information for process optimization and control.


Standard interfaces are 4..20 mA and Modbus/TCP. Other communication interfaces are available on request.

Several research organizations have contributed to the development of different sectors of ECT, including the University of Eastern Finland in Rocsole’s hometown Kuopio.

Important pioneering work in ECT was carried out at the US Department of Energy, Morgantown Energy Technology Center (METC) and at the University of Manchester Institute of Science and Technology (UMIST), and in UST for example at the Purdue University, USA.

Rocsole’s Tomographic Systems

Certainly. Rocsole’s sensors are tailored to fit the process. For example, SoliDetect sensor has measurement area of between 360 and 2880 mm, but the total length for a standard device is up to 4,3 m.

Sizes varies a lot according to sensor types. Sizes are usually available upon request. Please contact our sales team for support.

The weight depends on the types, sizes and material of sensors. For example, profiler 32 electrode (720mm measurement area) weighs approximately 34kg (75lbs), excluding M size electronic cabinet’s weight (IECEx certified) of about 45kg (139lbs), industrial PC shall weigh around 10 and 24 kg.

Rocsole’s system consists of the following components:

  • Sensor Unit
  • Electronics Unit, which contains the electronics components
  • Computer Unit, for computing and data transfer

Visit Technology page or contact our Sales Team for images and more information about the system components.

Stainless steel (1.4404/316L), Duplex Steel (1.4462), and super duplex (1.4410). Other materials may be available upon request. Please kindly note that different material might affect delivery time.

Depends on your application: SoliDetect & LiquiDetect for separators and tanks for example. Check the product pages for more information or contact our sales team.

Rocsole’s systems are available with ATEX/IECEx, MET C, MET US certifications. All systems meet requirements of the applicable EC directives.

Check Technology page or contact our Sales team for information on Rocsole’s sensor design standards and principles.

Process Conditions

Like with pressure, we can tailor the system to withstand high temperatures as well. Typically our sensors are designed for temperatures up to 155 °C / 311 °F, but we have manufactured sensors for processes that run at around 300 °C / 570 °F.

Ambient (environment) temperature range for electronics is typically: -40 and +50 ( -40 and +122 °F . In over 40 °C(104 °F) temperature the Electronics Unit may demand additional cooling.

Maximum pressure might vary according to sensor types, sizes and materials. As our sensors are tailored to your process, our sensors can withstand very high pressures.

We’ve delivered PIPE sensors that could handle 384 bar / 5569 psi. Design pressure for probe are currently 170 bar / 2464 psi.

Buying and delivery

Contact Rocsole’s sales for more information. We are happy to help.

As part of our subscription model we will deliver you our hardware unit and include any upgrades and updates. If we don’t have it in stock, typical delivery varies.


Yes, we offer on-site and and remote support services based on a customer specific contract.

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