FEATURE SPONSOR
CORROSION CONTROL
Figure 1: Ultrasonic inspection relies on echoes generated at the interface of non-corroded and corroded metal.
A PORTABLE SOLUTION When inspecting the hard-to-reach sections of a turbine tower, an important consideration is the portability of the inspection equipment. Rope access inspection is often required to inspect parts of the tower that are not accessible in other ways. For these types of inspection, handheld flaw detectors, such as the EPOCH 6LT, can be used. These devices can conveniently be strapped to a harness or leg for maximum freedom of movement.
The EPOCH 6LT weighs less than 1 kg and enables single-handed operation with all the controls readily available, even when wearing gloves. These features make it well suited for corrosion inspection in hard-to-access locations, as is the case with rope access inspections (figure 2).
The optional corrosion module of the EPOCH 6LT provides the best of thickness measurement and UT corrosion scanning in one instrument. It enables accurate thickness measurements, true V-path correction that accounts for the angle of dual element transducers and a function that compensates for wear on the transducer’s contact plate.
Conventional UT, which uses one single UT source, is the technology of choice for fast inspections with lightweight equipment. In order to inspect large areas of corroded materials with a very high precision and imaging capability, phased array ultrasound is an option. With phased array technology, long sections of metal can be inspected in a single scan with a resolution as low as 1mm. The resulting profiles clearly show
the extent to which corrosion has affected the tower and the safety implications of the corrosion.
WHAT IS PHASED ARRAY? In a phased array probe ultrasonic waves are generated, not from a single transducer, but from an array of transducers controlled by a single
For the inspection of complex shapes, many rigid probes have problems acquiring reliable data. These problems arise due to insufficient contact between the probe and the material. For these situations, a flexible probe provides the ability to acquire similar data from a curved or irregular surface.
FAST, RELIABLE INSPECTIONS The inspection of wind turbines involves examining large amounts of material in hard-to-access locations, such as the tower of the turbine. This type of inspection requires techniques that combine speed with reliability of the inspection. Ultrasonic technology, either conventional or phased array, is well suited for fast, high-resolution corrosion mapping in a range of components across different industries.
phased array flaw detector. These flaw detectors, such as Olympus’ OmniScan SX, control the delay between the firing of the different transducers, thereby enabling excellent control over the ultrasonic beam. One type of commonly used arrangement of transducers is the linear array. For maximum sensitivity, a linear array can be used in a pitch-catch setup; this so-called Dual Linear Array probe (figure 3) can be moved across the material’s surface to create an electronic scan.
FLEXIBLE DATA, FLEXIBLE PROBES The data collected in a phased array scan can either be viewed on-site or exported. Both B-scan and C-scan images can be created; these scans help to assess the type of corrosion. Data generated, for example in a C-scan thickness map, is conveniently exported in txt format for broad software compatibility.
Figure 3: The Dual Linear Array probe is a cost-effective corrosion inspection solution. When fitted with an Olympus encoder, the probe provides encoded C-scan imaging with 1 mm near- surface resolution.
Phased array flaw detectors, such as the Olympus OmniScan SX and EPOCH 6LT, provide intuitive, portable and easy-to- use solutions for the inspection of turbine towers. An inspector can use a range of different probes to evaluate large areas with high precision in less time, ensuring turbine safety and an efficient inspection workflow.
Olympus Europa SE & CO. KG
INSPECTION
WIND
DETECTOR
FLAW
CORROSION SOLUTIONS
www.windenergynetwork.co.uk 5
SCAN/CLICK
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77
