ERT vs. ECT.
Choosing the Right Tomography for Your Process.
Industrial tomography provides real-time, non-invasive imaging of processes inside pipelines, vessels, and reactors.
Understanding Process Tomography Measurements
Each method is suited to specific process challenges, helping industries optimise efficiency, improve product quality, and reduce operational costs.
The two primary measurement techniques used in ITS systems are:
Electrical Resistance Tomography (ERT)
Best for conductive materials such as liquids and slurries.
Electrical Capacitance Tomography (ECT)
Best for non-conductive materials such as powders and gases.
What is Electrical Resistance Tomography (ERT)?
ERT is designed for processes involving conductive materials, such as liquids, slurries, and emulsions. This method uses an array of electrodes placed around a pipe or vessel to send a low-level electrical current through the process material.
By measuring how electrical resistance changes, ERT can map variations in material concentration, flow patterns, and phase distribution.
Key applications include:
Mixing
Monitor blend uniformity and endpoint detection.
phase separation
Track liquid-liquid or liquid-solid separations.
reaction montioring
Optimise chemical reactions and crystallisation.
Multiphase Flow
Visualise gas-liquid or liquid-solid flow dynamics.
Why Use ERT?
Ideal for liquids and slurries with varying conductivity.
Provides fast, real-time imaging for dynamic processes.
Non-intrusive and can be used in hazardous or sensitive environments.
What is Electrical Capacitance Tomography (ECT)?
ECT is designed for processes involving non-conductive materials, such as powders, gases, and some organic liquids. Instead of measuring electrical resistance, ECT measures changes in electrical capacitance—the ability of a material to store electrical charge. This allows for detailed volumetric imaging of dry and gas-based processes.
Key applications include:
Powder Flow & Blending
Detect uneven distribution and segregation.
Pneumatic Conveying
Monitor gas-solid flow in pipelines.
Fluidisation & Packing
Optimise bed structures in reactors.
Material Distribution
Assess density and homogeneity in storage silos.
Why Use ECT?
Best suited for powders, gases, and non-conductive liquids.
Provides high-resolution imaging for material flow and blending.
Works in opaque and enclosed systems without disrupting operations.
ERT vs. ECT: Key Differences
Feature
Electrical Resistance Tomography (ERT)
Electrical Capacitance Tomography (ECT)
Best for
Conductive materials (liquids, slurries)
Non-conductive materials (powders, gases)
How it works
Measures electrical resistance (voltage changes) variations
Measures capacitance (permittivity) changes
Key applications
Mixing, separation, reaction monitoring
Powder flow, pneumatic conveying, material distribution
Imaging resolution
Fast, lower resolution
Higher resolution, slower response
Industries
Pharma, oil & gas, mining & mineral processing, chemicals
FMCG, food, pharmaceuticals
Non-intrusive?
Yes
No
Choosing the Right Tomography for Your Process
The right tomography technology depends on your material properties and process goals. Some industries use both ERT and ECT to complement each other in complex production environments.
