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Crack Detection, Material Sorting & Heat Exchanger Tubes Eddy Current Testing

Eddy Current Crack Testing Services in Bangalore, India at Peenya Indl Area

Crack Detection, Material Sorting & Tubes Testing

Eddy current testing-ET is a modern Nondestructive testing – NDT method. It is prime tool in controlling quality of components for Aerospace, automotive and heat exchanger tubes. Also, ET is used for inspection at various stages of manufacturing and in-service inspections.

Crack testing | Eddy Current Inspection

Eddy current is an NDT method for surface and subsurface crack testing. This method finds surface and subsurface flaws in any conductive material. Many applications are existing that use Eddy current principles. Present Eddy current NDT method has applications in Aerospace Component Inspections, Heat exchanger tube inspections in Oil Gas companies. Also, real time non-contact wall thickness testing, Material sorting, mixing, Paint and non-conductive coating thickness testing.

Demand for eddy current testing is steeply rising due to increasing usage of nonferrous materials. For example, Aluminium alloys for aerospace.

Applications | Eddy Current Testing

One of the major advantages of Eddy current testing is, the method is suitable for much more than flaw detection. In other words, the method is common for many applications. Trinity NDT has complete range of testing for the same at our NDT labs in Bangalore, India.

Eddy Current testing applications

  • Crack detection
  • Material sorting
  • Measuring conductivity
  • Coating thickness such as Non-conductive coatings on conductive materials. Also, conductive coating on conductive materials
  • Detection of heat damage on boiler and heat exchanger tubes
  • Case depth check
  • Monitoring of heat treatment process

Eddy Currents Crack detection

Eddy Current crack testing
Eddy Current machine for crack testing & material sorting

Crack detection on ferrous materials such as iron, nickel, cobalt based alloys is easy. Because, all ferro magnetic materials can undergo crack detection using magnetic particle inspection method. Then, what about other non-ferro magnetic materials? Such as Aluminium, or other non magnetic materials? Is there any NDT method to detect cracks on these materials? Answer is YES, Eddy current testing is one of the effective means of detecting cracks. The method can detect both surface and subsurface crack without even contacting the surface. Therefore, in many areas eddy current crack detector have replaced magnetic particle testing equipment where speed and accuracy is vital.

For example, eddy current machines detects cracks on railway tracks during manufacturing at steel plants. Also, as the method is contact less, high speed inspections are possible. In addition, unlike ultrasonic testing, no couplant is necessary.

Our Eddy current labs can provide you crack testing services both onsite across India and at our labs in Peenya, Bangalore.

Depth of Crack detection in Eddy Current machines

Like Ultrasonic testing-UT, this method can detect depth of surface and subsurface cracks with good accuracy. Depth of crack detection in Eddy Current depends on conductivity of materials and frequency of currents. To clarify, less is the conductivity of the material, better is the depth of penetration. Therefore, in highly conductive materials, depth is very minimal and limited to surfaces. However, in less conductive materials deeper cracks are detectable. In any case, usually depth of detection is three times the skin depth.

In conclusion, to improve the depth of penetration in high conducting materials we use lower frequencies.

Material Sorting or Mix up solutions

Eddy Current testing Crack detection
Eddy Current testing Crack detection

Material sorting or mix up is a common issue in workshops. As there are varieties of materials machined and heat treated, mix up commonly happens. If the mix up is based on chemistry variation, there are methods such as wet analysis, PMI etc., But these methods are time consuming and not cost effective. Then, which is the best NDT method for materials sorting? It is Eddy Current sorting.

Automobile components manufacturers are processing varieties of components. There could be variation in design, chemistry, heat treatment or other properties in materials. The most common issue in work floors is mix up of various grade of materials. Mix up could be either different chemistry or mechanical properties or metallurgical structures. Eddy current sorting is the cost effective and less time consuming means of arriving at right conclusion. Therefore, it is increasing becoming common to sort out the materials, using Eddy current sorting machines.

Portable as well as stationery type eddy current machines are available based on the volume of sorting and speed of sorting needed. Sorting could be based on chemistry, hardness variation or heat treatment condition. Eddy current sorting machines can do the job precisely. It could be manual sorting or fully automated machines for shop floor sorting. We have complete solutions on material sorting.

Measure Conductivity Using Eddy Currents

For a given material, conductivity depends on purity of metal. Therefore, by measuring conductivity we can estimate the purity of metals to a reasonable extent. Eddy current machines comes with conductivity test probes. %IACS ( International Annealed Copper Standard) is the unit for measuring conductivity of metals. Accuracy of testing depends on accuracy of calibration prior to testing.

We use NPL calibrated conductivity samples to establish the procedure. Do you need conductivity value or do you need sorting based on conductivity? Our ET labs have eddy current probes to test %IACS.

Measure Coating Thickness | Using Eddy Currents

Measuring coating thickness is important to ensure the quality of coating. It could be during manufacturing or during in-service inspection. In the sense, there could be conductive coating on conductive metals or non conductive coating on conductive metals. For example, paint or insulation on pipe lines or nickel or chromium plating on metals. Eddy current machines can help to estimate the thickness of these coatings. In fact, its a very good method for the purpose. There is still one limitation, that is the conductivity of coating and base material should have greater variation to get good results. Thus, ET is good to detect coating thickness using eddy current principles.

We have coating thickness samples traceable to national standards.

Eddy Current Testing of Heat Exchanger Tubes

Corrosion causes loss of wall thickness in heat exchanger tubes. This can lead to sudden failure of tubes in petroleum refineries. Eddy current bobbin probes helps to detect corrosion damages using dual frequency probes. By inter mixing the frequencies, suppression of signals due to noise or support plates is possible. Inner surfaces of tubes shall be clean to proceed for testing. Modern eddy current machines are highly reliable for testing corrosion during in-service inspections.

We have eddy current machines suitable for corrosion monitoring of heat exchanger tubes. If you need such services contact us today.

Find online offline Wall thickness of tubes | Eddy Current

Eddy current wall thickness is a modern NDT inspection method suitable for measuring low thicknesses. It could be in the order of few millimeters on conductive materials. For instance, ET is an accurate method, where there is a limit on using Ultrasonic machines.

Eddy current inspections can be either contact or non-contact type tests. Non- contact methods are suitable for online automation. This is to control thickness of wall, during making of Pipes,Tubes, Plates in real time. Of course, proper setup is the need of the hour to get accurate test results.

Aerospace Eddy Current In-service Inspections

Magnetic particle testing(MPI) is impossible to carried out on non-magnetic materials such as Aluminium and Titanium. In aerospace, Eddy current testing is common to find fatigue cracks on aircraft skins, fastener holes and turbine components during in-service inspections. The method is highly reliable. In addition, eddy currents can pass through even from some surface coatings. This reduces removal of coatings and restoring. Also, save time and thus cost of testing.

Further, for aerospace, speed of testing is vital. Therefore, high speed rotating scanners fitted to eddy current machines can perform bolt hole crack detection in a minimum of time.

Our eddy current labs in Bengaluru, India have machines and probes for inspection of Aircraft structures.

Eddy Current testing Services with NABL, Delhi accreditation

NABL, Delhi provide accreditation of testing labs on Nondestructive testing services. Trinity NDT Eddy Current Testing labs have accreditation for eddy current testing as per ISO17025:2017.

Download NABL Certificate | Scope of NABL

Impedance plane display machines have built in defect recording makes testing and printing reports easy. It could be crack detection or material sorting or heat exchanger tube inspection, we are ready to serve you from our NDT labs in Bangalore, India.

We at ‘Trinity NDT’ provide reliable inspection services on Eddy current testing fine tuned to the client needs. Our ET NDT Level II Inspectors are ready to carryout testing in house and onsite. Working under ASNT Level III gives the best view of inspections. Therefore, our NDT inspectors have good skills to give you the best solutions on eddy current testing.

In addition, we also give you ASNT NDT Eddy current testing ET Level III services for procedure preparation and approval. If you need any NDT procedure preparation for your jobs or setup lab contact us today. Want to know more about our other NDT testing services ? Visit the below.

Courses on Eddy Current Testing Level II | NDT Training on ET

We offers the best courses and training to certify for Eddy current ET Level I and ET Level II.  The courses will be as per ASNT SNT TC 1A.  Training is through our training centre at Bangalore – India. We can offer you the same training or specific training at your location. Contact our training department today for more details.

We are serving pan India including Chennai, Mumbai, Kochi, Hyderabad, Vizag, Jaipur, Kolkata, Delhi, Pune, Nagpur, Patna, Mangalore, and Hosur. Send us your query or request for quote for our NDT testing services Now. 

What is the principle Of Eddy Current Testing | Learn Basics

When a test conducting object is brought close to the AC field of test coil, flux causes electrons to circulate in a swirling eddy-like pattern in the object; thus the term ‘eddy currents’. In other words, eddy current behavior depends on the properties of both the flux and the object itself. Therefore, eddy currents are circular AC currents caused by a varying magnetic field. It works on the principle of ‘EM induction’. If there is a change in current flow path, that will provide an indication on screen.

Are you looking for free eddy current test procedure or report format? Here, we give you useful NDT procedures and test report formats for free in pdf.

Advantages | Eddy Current Testing

  • This NDT method is sensitive to small cracks and other defects
  • Detects both surface and near surface defects
  • Gives faster results
  • Portable machines
  • Can be used for much more than flaw detection
  • Minimum part preparation is needed
  • Probe need not contact the part surface
  • Finally, Tests complex shapes and sizes

Limitations | Eddy Current Testing

  • Suitable for only conductive materials
  • Surface must be accessible to the Eddy current probe
  • Skill and training required for testing is more than other methods
  • Surface finish and roughness may interfere with test results
  • Reference standards needed
  • Depth of penetration is less
  • Flaws that lie parallel to the probe coil winding and probe scan direction are not detectable. These may get detected only using special probes.

Want to learn more about ET & Nondestructive testing? Contact us for information on courses eligibility, fee structure and training schedules.