Tech Showcase: Eddy Current Today
Performing the test in the correct environment with the best technique is crucial, as is the choice of instruments. A selection of eddy current testers is listed below. No matter what the application, a tester is likely available to get the job done.
Olympus (www.olympus-ims.com) introduces a new series of NDT tube testing probes that can be successfully used to inspect heat exchangers, feedwater heaters and boiler tubes. These probes use remote field testing technology (RFT) to inspect ferromagnetic tubing such as carbon steel or ferritic stainless steel. The new RFT probe series, TRS, TRX, and TRT, detect and measure volumetric defects resulting from erosion, corrosion, wear and baffle cuts. The series of products has improved signal clarity and detection capabilities, particularly on the differential channel. The signal-to-noise ratio is increased with improved electronics and preamplifier. The thicker probe casing and the flat probe tip also improve the durability of the probes.
The RFT probes can be used with the Olympus MS5800 multitechnology inspection system. In addition, Olympus is introducing several new accessories for the MS5800 including the MS5800, Backpack, Footswitch and the Airgun. The MultiScan MS5800 instrument, MultiView software and the tube inspection probes have been developed for today’s industries’ tube inspections needs. In continuous development, a new version of Carto software is available. This graphical tool draws simple or complex tube sheet maps and transforms inspection data into accurate and concise color-coded reports.
Flexibility is key with Apollo, which can be used in both multiplexed and simultaneous injection modes. The software behind it is industry proven for increased productivity and is easy to use for small inspection scopes, while still having the power required for large-scale inspections. Its lightweight design and digital capabilities are well suited for simple, single-person operations as well as large outages where multiple testers and large data rooms are required. Its durability and portability make it ideal for applications such as ferrous and non-ferrous in-service tube testing and surface component testing. Additional features include full signal capture, configurability up to 1024 channels and 256 frequencies, a frequency range of 1 hertz to 10 megahertz and automatic gain control.
TecScan’s bearing inspection system is a turnkey solution. The system includes the four-axis scanner, all required operating electronics and an external eddy current instrument-all of which are completely integrated to its TecView EC software package. TecView EC is tailored to bearing inspections, with features including multiple alarms, track display and automatic generation of inspection reports.
The MECA-probe can detect very small cracks on hardened CAMs based on surface conditions, such as ground surface with crack depths of less than 0.10 millimeter or forged surfaces with crack depths of less than 0.25 millimeter, as well as the detection of grinding burns and grinding cracks. When scanning the surface of asymmetrically shaped CAMs, not only single cracks but also fine networks of cracks can be detected with a high signal-to-noise ratio at rotational speeds up to 180 rpm. For the testing of CAMs, Foerster has developed a testing station that allows CAMs to be tested more effectively and efficiently. With a cycle time of up to 4 seconds per CAM, this station contains all the elements of a modern CAM testing system. The MECA-probe offers high test speed/throughput, high test sensitivity and optimized handling.
The ED-400M is a self-contained electronic instrument that offers high sensitivity, making it ideal for quick, reliable crack detection. After the probe is electronically balanced, the operator slides the probe over the inspection piece, keeping an eye on the meter. The meter needle then deflects, pinpointing the location of the flaw. Audio and visual alarms also can be set to alert the operator.
The instrument also is not affected by changes in background magnetic permeability. Thus, the tester requires no adjustment when inspecting for defects through surface rust, oxides, paint or other coatings. In addition, minor movements in probe alignment during inspection do not seriously affect the meter reading.
With applications ranging from weld inspection and maintenance to receiving inspections and process control, the ED-400M can be used to complement or replace magnetic particle inspection methods in several industries, including automotive, construction and oil and gas pipelines.
Measuring 5 inches high by 9 inches wide by 6 inches deep and weighing 5.3 pounds, the ED-400M is suited for the most rugged environments. Long-life, rechargeable nickel-cadmium batteries provide up to 50 hours of continuous operation on a single charge. A vast selection of probes is available to meet the needs of most applications. Special probes also may be designed for unique applications.
Calibration is comprised of taking signals (noise) from surface areas of good parts and recording these signals simultaneously in each of a large number of band pass filters (up to 30). Simultaneously universal tolerance fields are generated uniquely for each filter setting. In test mode, any type of flaw is automatically detected if its signal exceeds the universal tolerance field threshold in any band pass. Thus, all flaw types are reliably detected with high signal-to-noise ratio. Use of a high number of band pass filters and universal thresholds in each guarantees automatic, high-resolution detection of all flaw types, even unexpected types, regardless of frequency content and phase angle. The signal need only exceed the universal threshold.
The instrument facilitates setup and operation by semi-skilled personnel. Its features include a 15-inch color touch screen; up to 16 test channels; lift off compensation; advanced software for easy operation; various graphic data displays including bar graph, tolerance fields, X/Y, X(t), Y(t) and C-scan; interfaces include USB 2.0 (3), Ethernet, PC and printer (USB). Interface to PLC to control automated testing is provided by opto-isolated interface with 64 (option 128) inputs and outputs.
From a small number of accept/reject part tests, the instrument will automatically select the optimum test frequency, test method (phase or amplitude) and sort limits for testing. Built-in SPC capability is enhanced by the ability to download the data in memory to floppy disks, hard drives, monitors or other programs for further analysis. A single battery charge permits up to 8 hours of continuous portable operation. An internal charging circuit is provided, along with an AC adapter for in-place testing. Line voltages are easily switch-able from 110 to 220.
The Verimet 7700 tests any size part from small-diameter needle bearings to huge tank turret bearing journals. Standard connectors allow quick changeover from probes to coils.