Types of Eddy Current Flaw Detectors
Eddy current testing (ECT) is a nondestructive testing (NDT) inspection method used for a range of applications. These include flaw detection, material and coating thickness measurement, testing conductivity, and more. Flaw detection involves identifying surface and subsurface defects, linear defects, cracks, lack of fusion, or general corrosion on partially ferromagnetic materials, such as nickel alloys, and thin-ferromagnetic materials, such as stainless steel. There is a range of different ECT flaw detection technology available to users, and each has its strengths and weaknesses depending on the application. In this article, we will discuss the different types of eddy current flaw detectors and help you decide which is best for your industry.
What Is an Eddy Current Flaw Detector?
Eddy current flaw detectors are used to inspect metallic parts and perform highly reliable flaw detection of surface and subsurface defects. They do this by generating a magnetic field using an alternating current flowing through a wire coil. When the eddy current flaw detector is moved close to a test material it creates a circular flow of electrons known as an eddy current that will begin to move through the test material. The eddy current flow generates its own magnetic field, which then interacts with the coil in the flaw detector and its field through mutual inductance. Surface or subsurface defects will interrupt the amplitude and pattern of the eddy current flow and the resulting magnetic field. Eddy current flaw detectors recognize changes in the impedance amplitude, which can be used by trained operators to identify these defects.
Olympus Flaw Detector Technologies
In this section, we will look at the different Olympus eddy current flaw detectors, comparing their key features and what they are used for.
NORTEC™ 600 Flaw Detector
The NORTEC 600 eddy current flaw detector comes with a 5.7-inch VGA display capable of full-screen mode, which produces clear and contrasting eddy current signals in any lighting condition. The NORTEC 600 instrument uses the latest high-performance digital circuitry and comes in one compact, portable unit. The NORTEC 600 instrument is built for endurance in harsh in-the-field conditions and its durability and resistance to extreme weather are its key features. If you want to carry out flaw detection in unpredictable conditions, this is a reliable technology.
MultiScan MS5800™ Multitechnology System
The MultiScan MS5800 system is designed for tube inspection in products such as condensers, feedwater heaters, heat exchanges, and air conditioners. It uses two coils excited with an electrical current to produce a magnetic field. The magnetic field is used to penetrate the tube material and generates opposing alternating currents. Any defects will be identified through changes to the eddy current flow. The MultiScan MS5800 system is designed for fast inspection, and has four simultaneous frequencies per input enabling inspection speeds of up to 2 m/s. It also has four eddy current testing (ECT) inputs and up to 64 multiplexed channels, meaning it can support a large number of ECT channels to perform eddy current array (ECA) probe inspections. If you’re looking for NDT technology that can carry out fast, accurate inspections of tubes, the MultiScan MS5800 flaw detector is the multitechnology system you need.
Eddy Current Probes
Eddy current probes are lightweight inspection tools used for ferromagnetic or nonferromagnetic part and material inspection applications. Eddy current probes can be used across a range of applications, and you can learn more about the different types of probes and which is best for your industry here.
OmniScan MX Modular Flaw Detector
The OmniScan MX ECT/ECA flaw detector is built to withstand harsh and demanding inspection. It uses eddy current testing (ECT), eddy current array (ECA), and bond testing (BT) technology to meet a broader range of inspection requirements. The OmniScan MX flaw detector is most commonly used for stress corrosion detection, ECA surface and subsurface crack detection, ECA subsurface corrosion detection, and carbon steel surface examination. Key features of the OmniScan MX unit include its compact, lightweight design and its two Li-ion batteries that provide up to six hours of manual or semiautomated inspection time.
Rotating Bolt Hole Scanners
Rotating bolt hole scanners are commonly used for applications such as airframe hole inspection, wheel bolt hole inspections, surface inspections, post-production testing for cracks, tube plug testing, and low-frequency inspections of aircraft. For use with eddy current flaw detectors, these devices have a wide range of features consisting of speed ranges from 600 to 3000 rpm, frequency ranges from 100 Hz to 6 MHz, multiple connector types, and multiple probe types. The different probe types include:
- Reflection differential
- Absolute bridge
- Absolute reflection
- Differential bridge
- Differential reflection
You can learn more about Olympus bolt hole scanner specifications here.
Olympus technology can be used to meet a range of nondestructive testing applications across different industries. Visit our website to explore the eddy current flaw detector solutions we offer and learn how our technology can help you meet demanding quality standards and industry regulations.
