ECT Instruments ERT Series Capacitive Tomography System

Overview

The ECT Instruments ERT Series Capacitive Tomography System is a high-fidelity, non-invasive industrial process imaging platform engineered for real-time visualization of dielectric material distribution in opaque multiphase flows. Based on the physical principle of electrostatic capacitance tomography (ECT), the system reconstructs cross-sectional permittivity maps by measuring minute inter-electrode capacitance variations—typically in the sub-femtofarad range—across an array of strategically arranged electrodes mounted on the outer surface of a pipe or vessel. Unlike optical or radiation-based modalities, ECT operates without ionizing sources or intrusive probes, making it intrinsically safe for continuous operation in hazardous, high-temperature, or high-pressure environments typical of chemical processing, pneumatic conveying, fluidized beds, and pharmaceutical powder handling. The system’s core architecture integrates precision analog front-end electronics, programmable DDS excitation, synchronized multi-channel acquisition, and robust image reconstruction algorithms—all calibrated to deliver reproducible, quantitative spatial data under laboratory-grade conditions (0–50 °C ambient, 10–240 V AC, 50–60 Hz).

Key Features

• Modular Eurocase-based hardware platform (19″, 3U, 84HP) with DIN41612-compatible backplane for scalable expansion
• Dual 8-channel capacitive measurement boards supporting up to 16 electrodes; adaptive measurement range: 0–2 pF with <0.1 fF resolution and 73 dB SNR
• Two independent DDS signal generator boards: fully programmable sine-wave excitation (up to 1 MHz), amplitude up to 20 V_p-p, phase shift resolution 0–360°
• NI PCI-6024E 16-channel DAQ board with 12-bit ADC/DAC, 24 DI/DO lines, and >100 frames/s throughput (12-electrode configuration)
• Integrated power supply delivering +5 V (3 A), ±15 V (1.5 A / 0.5 A) DC with CE certification and 25 W max consumption
• Compact footprint (50 × 12 × 27 cm), lightweight design (~5.1 kg), and SMB-to-electrode interface for rapid sensor integration

Sample Compatibility & Compliance

The ERT system is compatible with standard and custom-built electrode sensors (e.g., 8-, 12-, or 16-electrode configurations) fabricated from stainless steel or corrosion-resistant alloys, suitable for cylindrical pipes ranging from 50 mm to 300 mm ID. It supports insulating liners (e.g., PTFE, ceramic) and operates independently of fluid conductivity—enabling imaging of gas-solid, liquid-gas, and immiscible liquid-liquid systems. Hardware and firmware comply with CE marking requirements (EMC Directive 2014/30/EU and Low Voltage Directive 2014/35/EU). While not certified for SIL or ATEX use out-of-the-box, the system’s intrinsic safety profile and absence of active internal radiation sources facilitate integration into IEC 61511-compliant control architectures when paired with appropriate barrier systems. Data acquisition workflows support GLP-aligned documentation practices, including timestamped raw binary logging and audit-ready calibration records.

Software & Data Management

The native software suite—developed in Visual C++ and validated on Windows XP/Vista—provides full lifecycle management: sensor calibration, real-time acquisition, offline reconstruction, and export-ready post-processing. Core modules include: (i) System Test Suite (DC offset, gain linearity, and frame-rate validation); (ii) Acquisition Engine with configurable excitation patterns, electrode pairing schemes, and normalization routines; (iii) Reconstruction Kernel offering Linear Back-Projection (LBP) with precomputed sensitivity maps (8-/12-electrode variants) and Landweber iterative regularization (programmable relaxation factor and iteration count); and (iv) ASCII/Binary Converter for interoperability with MATLAB, Python (NumPy), or third-party visualization tools. All raw measurements are stored in binary format with header metadata (timestamp, electrode configuration, excitation parameters), ensuring traceability per ISO/IEC 17025 clause 7.5.1. Software installation requires Intel Pentium IV 2.0 GHz (or AMD Athlon equivalent), ≥512 MB RAM (2 GB recommended), 1 GB free HDD space, XGA display, and one available PCI slot.

Applications

The ERT system serves as a research and diagnostic tool across multiple engineering domains: monitoring solid concentration profiles in dilute-phase pneumatic transport; quantifying bubble size distribution and gas hold-up in stirred-tank reactors; characterizing segregation dynamics in rotating drum mixers; validating CFD-DEM simulations of granular flow; and detecting blockages or slug formation in oil-water pipelines. Its ability to resolve permittivity contrasts between phases—without requiring optical access or radioactive tracers—makes it particularly valuable for process development under GMP-relevant conditions where equipment qualification and data integrity are mandated. Academic users leverage its open API and MATLAB compatibility for algorithm development, while industrial clients deploy it for comparative benchmarking against gamma-ray or electrical resistance tomography (ERT) systems.

FAQ

What is the maximum electrode count supported by the standard ERT system?

The base configuration supports up to 16 electrodes via dual 8-channel measurement boards; custom configurations with expanded backplane and DAQ can accommodate up to 24 electrodes upon request.

Does the system provide built-in temperature compensation?

No—the system assumes stable ambient temperature (0–50 °C) and does not include integrated thermal sensors; external environmental monitoring is recommended for long-term stability studies.

Can raw capacitance data be exported for third-party reconstruction?

Yes—binary files contain unprocessed capacitance values with full metadata; ASCII conversion utility enables direct import into MATLAB, Python, or Excel for custom inversion or machine learning workflows.

Is FDA 21 CFR Part 11 compliance supported?

The base software does not include electronic signature or audit-trail functionality; however, raw data logs and reconstruction parameters are fully deterministic and timestamped—enabling integration with validated LIMS or ELN platforms that enforce Part 11 requirements.

What maintenance is required for long-term operational reliability?

Annual verification of DAC/ADC linearity, excitation amplitude stability, and electrode cable impedance is recommended; no consumables or recalibration kits are required beyond routine visual inspection of connectors and grounding integrity.