A revolutionary tool for eddy current nondestructive evaluation
Sciensoria has released ConducsensTM, a new eddy current non destructive evaluation system for the measurement of thickness, electrical conductivity, magnetic permeability of non magnetic and magnetic metals, graphite, and carbon fiber composite materials. In many cases, no calibration is needed because the Conducsenstm has a self-calibration function.
Demo videos available (see under the pictures)
The eddy current non destructive testing/evaluation method uses a alternative magnetic field to excite a conductive target in order to create induced currents in it. These currents are called "eddy currents". When flowing inside the target, the eddy currents work as probes. They can reveal the internal state of the target through the secondary magnetic field that they create in the space around the target.
In order to create the alternative magnetic field, an alternative current of frequency f is injected into a coil. The magnetic field will induce eddy current to conductive materials near the coil. The eddy currents create their own magnetic field which tends to opposite to the exciting field. The sum of these fields is different from the exciting field in magnitude and phase angle. The induced voltage across the coil is an image of this field, it can be monitored in order to determine the characteristics of the target.
This phenomena is similar to a transformer: the target is the secondary circuit of the transformer. The difference is that the "secondary circuit" of a transformer is constant, while eddy currents in a target change as function of many parameters: the coil-target distance, the target's conductivity, magnetic permeability, thickness, etc... When there are flaws inside the target, magnetic field on its surface can changes locally, the changes can be detected by a small detector or by differential probes.
An eddy current probe is sensitive to many parameters at a time. This is an advantage because one can use it for many purposes, but also a problem because it may be difficult to distinguish the effect of each parameter. In order to measure a parameter, the measurement system needs to be calibrated: the user has to acquire eddy current signal on reference standards where only the parameter to be measured varies, while the other parameters are kept constants. This process is quite long, difficult and expensive.
We have invented the Conducsens(tm) system which can be calibrated with respect to various parameters changes "one time for all". The calibration result is recorded into a computer program called "model". When in use, the system does not need to be recalibrated on various calibration gauges and can give correct result. If necessary, an extra calibration on only one calibration gauge can be carried out in order to remove offset and improve accuracy.
The Conducsens(tm) is composed of a special probe, a program for Windows computers, and a connected impedance analyzer. Many models of impedance analyzers are compatible: Keysight (former Agilent), Hioki, IetLabs, etc..
Illustration of an eddy current testing (left) and the equivalent circuit (right)
Behaviour of the magnetic fields around an excited target
Behaviour of the eddy currents inside a target with a slot inside
Sciensoria is a French company specialized in eddy current non destructive testing and instrumentation.
We develop probes, softwares, and signal conditionners.
Our most important development is the Conducsens(tm) & TK-Sens(tm) system which allows to measure physical properties and thickness of a wide range of materials.
We also offer feasibility study, material characterization services, probes design and manufacturing, special hardware design.
We are always look for ways to make further improvements of our techniques. We have made new software/hardware solutions which change totally the way to do Non destructive Testing.
We have found solutions for some difficult applications:
Currently, we are working on some exciting probes for flaws detection on tubes, including rotating field probe.
We propose eddy current probes, probes conditionners, general purpose eddy current instruments, signal processing softwares.
Beside this, we also propose custome solutions for specific applications. Please do not hesitate to contact us to talk about your application.