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|NDT.net Issue - 2015-05 - NEWS ||NDT.net Issue: 2015-05|
Publication: e-Journal of Nondestructive Testing (NDT) ISSN 1435-4934 (NDT.net Journal)
The advantages and disadvantages of advanced NDTAshtead Technology16, Letchworth Garden City, United Kingdom
Simple, conventional inspection methods such as ultrasonic thickness testing can provide a useful, fast, low-cost method for assessing materials. However, in comparison with advanced NDT, such methods are generally less repeatable, less recordable, and have a lower Probability of Detection (PoD).
There are many advantages to be gained from advanced NDT, some of which will be briefly described below. The major disadvantage of these high-end technologies is, of course, their cost. Advanced NDT instruments may cost tens of thousands of pounds and require significant levels of training to best exploit their benefits. For this reason, Ashtead Technology has chosen to invest over £1 million in advanced NDT equipment; the ability to rent this technology can dramatically lower the cost of entry to this market for our customers in applications such as crack and flaw detection, weld evaluation, tube testing, corrosion mapping, composite inspection etc.
The advantages of advanced NDT
With greater control over instrument configuration, advanced NDT procedures can be optimised for particular inspections. Setup files can be saved digitally and easily transferred to others. Digital recording means that data can be emailed to colleagues when a second opinion is required, or when complex data needs to be assessed by a higher level technician. The ability to store large inspection data files also means that new inspections can be compared with those done previously, to determine whether there has been further deterioration, and to monitor, for example, crack growth. In addition, the use of scanners improves repeatability and helps to ensure that sequential inspections are directly comparable and less subjective.
As a result of these advantages, there has been strong growth in the advanced NDT sector, and this has been reflected in the volume of advanced NDT instruments in the Ashtead Technology fleet that are out on hire.
The disadvantages of advanced NDT
Purchase of a particular technology may also reduce or preclude access to other methods that may be developed at a later date.
It is important to remember that the capital expenditure on advanced NDT equipment is not the only cost. Instrument maintenance incurs a further cost, as does depreciation. Capital purchases will typically be written off in the company accounts over a 3 year period, which means that this equipment must generate substantial profit for a return on that investment. Also, there are borrowing and opportunity costs - the money used in equipment purchase or to pay interest could have been used for something else, such as training or hiring more staff.
To be a worthwhile investment, high value advanced NDT equipment must be used regularly. Without an assured steady flow of work, there is a danger of underutilisation. In contrast, renting provides a way to only pay for equipment when it is needed and not to incur any costs in the intervening periods.
In summary, the advantages of advanced NDT can be enormous if the financial implications are managed effectively. One way to achieve this is by taking advantage of rental instrumentation from Ashtead Technology.
Author: Alison Glover, Ashtead Technology
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