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The surface quality of a material significantly affects the accurate measurement of the ultrasonic attenuation coefficient. In this research, a roughness correction method for experimental calculation of the attenuation coefficient using contact transducers is proposed. Firstly, the losses due to the scattering from a rough interface are analysed. According to the mechanism of ultrasonic waves reflected from a thin layer between two solid media, the frequency-dependent reflection coefficient of the coupling interface involving a roughness parameter is derived based on the phase-screen approximation theory. Then, a compensation model is established to correct the error caused by the surface roughness. 304 stainless steel and 45 steel specimens with different levels of surface roughness are prepared and ultrasonic measurements are implemented using both the through-transmission and pulse-echo methods. The experimental results show that the proposed correction method can effectively eliminate the losses caused by surface roughness and improve the measurement accuracy of the attenuation coefficient. [ABSTRACT FROM AUTHOR]

Laser ultrasonic waves are promising tools for non-destructive inspection in various industries. To inspect an entire object, the laser beam must scan the complete surface of the object. The incident angle of the laser beam will then differ depending on the location on the object that is irradiated. While oblique incidence of the laser beam will excite ultrasonic waves, there is a possibility that these waves will be different from those excited at normal incidence. For the establishment of reliable inspection techniques, a deeper understanding of laser ultrasonic waves is required. In this paper, the generation of ultrasonic waves by lasers at oblique incidence is numerically investigated. An integral expression for the temperature distribution that satisfies the thermal conduction is derived and then finite element method (FEM) simulations of the generated elastic waves are performed. In the case of a small incident angle of the laser beam, the directional dependence of the generated ultrasonic waves is small. However, with a large incident angle, the generated waves exhibit directionality in the wave intensity. Although the incident angle does not need to be considered in the ordinary use of laser ultrasonic devices, the detectability of defects may be affected when the angle is very large. [ABSTRACT FROM AUTHOR]

Austenitic stainless steels are widely used in the key components of major equipment and the welds can be the weakest parts of equipment made with these materials. Ultrasonic waves propagate in austenitic stainless steel welds with multiple paths and modes. This study employed a multi-view total focusing method using an ultrasonic phased array for defect detection in the welds of small-diameter austenitic stainless steel pipes. The detection capability of four different direct wave modes and eight different half-skip wave modes for typical defects were compared and analysed through numerical simulation. A fusion imaging method was developed using the preferred direct and half-skip wave modes. The process was further verified with a weld defect detection experiment carried out on small-diameter austenitic stainless steel pipes. The results show that the multi-view total focusing method can efficiently detect the defects in the welds of small-diameter tubes. Compared with the single-mode imaging method, the fusion total focusing imaging approach can not only improve the signal-to-noise ratio but can also reduce the number of image artefacts. [ABSTRACT FROM AUTHOR]

In this study, three aluminium samples produced by wire + arc additive manufacture (WAAM) are inspected using ultrasonic phased array technology. Artificial defects are machined using a centre drill, ø 3 mm, and electrical discharge machining (EDM), ø 0.5-1 mm, in a cylindrical through-hole topology. The samples are first inspected using a singleelement wheel probe mounted on a KUKA robot in order to investigate the feasibility of using a conventional ultrasonic transducer approach. Unfortunately, the wheel probe is found to be unsuitable for scanning the WAAM specimens and ultrasonic phased arrays are employed next. The set-up includes 5 MHz and 10 MHz arrays (128 elements) in direct contact with the sample surface using both the conventional and total focusing method (TFM) imaging techniques. Using an FIToolbox (Diagnostic Sonar, UK) as the controller, a phased array aperture of 32 elements is used to perform a focused B-scan with a range of settings for the transmit focal depth. All of the reflectors (including those located near the WAAM top surface) are successfully detected with a combination of conventional phased array and TFM, using a range of settings and set-ups, including bottom surface inspection, application through a plexiglass wedge and variation of the scanning frequency. [ABSTRACT FROM AUTHOR]

In this paper, a non-destructive method for determining the thicknesses of dual-layer coatings is developed using an ultrasonic spectral filtering technique based on the theoretical investigation of wave propagation in specimens with two layers and three interfaces. The acoustic reflection coefficient of dual-layer coatings was separated from the measured signal through Fourier transformation and Wiener deconvolution. Utilising the multi-frequency windows autoregressive spectral extrapolation (MARSE) technique, the cosine signals (sine signals), including the time-of-flight (TOF) of each layer, were split from the real part (imaginary part) of the acoustic reflection coefficient. The thicknesses of the dual-layer coatings were calculated utilising the periods of the cosine signals (sine signals) and the longitudinal wave velocities of each layer. Ultrasonic experiments were carried out on the dual-layer coatings, where the thicknesses of layer 1, layer 2 and the aluminium substrate were 230 μm, 450 μm and 5 mm, respectively. The thicknesses measured by the proposed ultrasonic method were in good agreement with those observed by optical microscopy (OM) and the relative errors of layers 1 and 2 were both less than 5.0%. [ABSTRACT FROM AUTHOR]

Since the introduction of full matrix capture to non-destructive testing (NDT), there have been advancements in software algorithms allowing for fully-focused imagery to be generated. Due to the large number of time-domain signals associated with this approach, processing speed is often a limiting factor. This paper describes an alternative, less processor-intensive approach in which a parallel transmission of a highly divergent beam is generated to simulate a virtual point positioned some distance behind the transducer. When combined with each element of the array acting as a receiver, sufficient time-domain signals may be acquired to allow fully-focused imagery to be generated. [ABSTRACT FROM AUTHOR]

This work aims to enhance the filtering performance of the recursive least-squares adaptive algorithm in the ultrasonic testing of materials by processing the primary input of the filter to improve the correlation properties of the signal and noise and enhance the adaptation and filtering process. The preprocessing is carried out using the SURE and universal threshold methods, which were originally used in wavelet denoising. The standard and proposed realisations of the recursive least-squares filter were applied to process simulated ultrasonic grain noise signals and the echo signals of experimental defects. Preprocessing using the SURE method did not offer good results in the simulation study. The results of the simulation and experimental studies showed that the proposed configuration of the recursive least-squares filter using the universal method performs better than the standard recursive least-squares filter. [ABSTRACT FROM AUTHOR]

Radiometric testing is one of the non-conventional non-destructive evaluation methods that has found wide applications, especially in the nuclear industry for evaluation of the integrity of components in nuclear reactors and fuel cycle facilities. In this method, the transmitted intensity of radiation is measured and then correlated to dimensional variations or gross defects, such as voids in materials. India has embarked on a three-stage nuclear programme, with the second stage focusing on sodium-cooled fast reactors. At Kalpakkam, an indigenously-designed 500 MWe prototype fast breeder reactor (PFBR) using mixed oxide as fuel and sodium as coolant is under construction. This is a pool-type reactor in which the entire in-core components will be immersed in sodium. As liquid sodium is opaque to visible light and conventional visual methods based on charge-coupled devices (CCD) cannot be used, ultrasound waves are used to visualise the components immersed in sodium. It is essential to know the position and protrusion of fuel sub-assemblies inside the core. An innovative, ultrasonic under-sodium scanner (USUSS) has been developed for this purpose. USUSS is a slender structure consisting of two detachable parts known as the lower and upper parts. This shield plug is designed to protect personnel and components from the intense gamma radiation. In this paper, the authors focus on the application of radiometric testing for evaluating the integrity and shielding effectiveness of the shield plug. A 60Co source of strength 31.5 MBq was used as the source and measurements were made using a NaI(Tl)-based portable gamma spectrometer. Radiometric testing confirmed that all dimensional variations were well within the 3% tolerance limits and the material was free from major voids and defects. [ABSTRACT FROM AUTHOR]

The article lists several papers and presents abstracts related to nondestructive testing (NDT) including ultrasonic systems, NDT of glass-fibre polymer-matrix composites using dielectrometry sensors and NDT of honeycomb sandwich structure.

Visual inspection is currently the most commonly used method for monitoring the degradation of in-situ stud bolts in service, often supplemented with a sample removal of bolts for closer examination. An industry guideline document produced by the Energy Institute for bolted connections includes references to an operator's performance standard, stating that bolts with a 10% loss of major diameter shall be replaced with new bolting. Phased array (PA) and other ultrasonic (UT) systems for bolt inspection are available but to date have not been widely used for corrosion inspection. This study investigates the performance of three different ultrasonic NDT methods for the evaluation of in-service bolt corrosion (PA, manual pulse-echo and a pitch-catch technique). Four separate blind trials were performed by different companies using probes on one end or, in one case, both ends of the bolts (pitch-catch). It was found that the detectability of corrosion generally decreased significantly with the range from the probe and increased with the extent of the diameter loss. A 10% diameter loss could only be detected within about 50 mm of the inspected end of the bolt. However, all trials showed high false-call rates, similar to the overall flaw detection frequency, which raised concerns about the overall value of the inspections performed. [ABSTRACT FROM AUTHOR]

The present economic climate is focusing downstream oil companies on maximising the use of their production assets. The major driver for this has been the reduction in maintenance periods with the emphasis on increasing activities that can be carried out when the plant is on stream. Inspection on stream has many advantages for the operator, the more obvious being that there is no requirement to shut their plant down. Other gains to be made are that there can be better planning for any subsequent remedial action before any planned shutdown. This paper will discuss the progress made by TÜV Rheinland Sonovation in the application of conventional and automated ultrasonic techniques leading to the present capability of inspection at 900 degrees Fahrenheit (480°C). Explanations will be given as to how this was achieved, with the attendant considerations on health and safety and application problems with the required calculations. In addition, several case studies will be presented. [ABSTRACT FROM AUTHOR]

The article focuses on an observational finding of discrimination criteria between planar and volumetric faults through ultrasonic pulse-echo or phased array method grounded on the ratio of diffracted echoes in welding testing. It presents the confirmation whether the modulation value modeled by the method is consistent with the examinations through fracture mechanics criteria. It also shows if the element condition can be examined applying the applicable criteria for the type of defects.

The increasing deterioration of panel paintings can be due to the physical processes that take place during exhibition or transit, or as a result of temperature and humidity fluctuations within a building, church or museum. In response to environmental alterations, a panel painting can expand or contract and a new equilibrium state is eventually reached. These adjustments, though, are usually accompanied by a change in shape in order to accommodate the new conditions. In this work, a holographic method for detecting detached regions and micro-cracks is described. Some of these defects are confirmed by the thermographic signal reconstruction (TSR) technique. In addition, pulsed phase thermography (PPT) and principal component thermography (PCT) allow two artificial defects in Mylar to be identified with greater contrast, which is crucial to understand the topic of interest: the discrimination between defect materials. Finally, traditional contact ultrasound applications are widely applied for the evaluation of the wood quality in several characterisation procedures. Inspecting the specimen from the front side, the natural and artificial defects of the specimen are confirmed. Experimental results derived by the application of the integrated methods on an Italian panel painting reproduction, called The Angel specimen, are presented. The main advantages that these techniques can offer to the conservation and restoration of artworks are emphasised. [ABSTRACT FROM AUTHOR]

The reliability of the ultrasonic technique for corrosion monitoring was assessed by using bivariate least squares (BLS) regression. The loss of thickness in corroded samples was measured using micrometer and ultrasonic methods. Micrometer measurement is quite accurate but it requires access to both sides of the structure. On the other hand, ultrasonic thickness measurement is fast but its accuracy is often doubtful. If both methods provide mean readings with comparable accuracy, then applying BLS regression would produce a straight line with an intercept and slope that are not significantly different from 0 and 1, respectively. A statistical test was applied to compare the obtained intercept and slope values with their respective theoretical values. In this work, a thickness gauge and a flaw detector were used to measure a thickness loss between 0.20 mm and 2.20 mm. The results showed that the mean measurement using the thickness gauge is more accurate than that using the flaw detector. [ABSTRACT FROM AUTHOR]

The article offers information on various welding products. It states that ultrasonic motor (USM) Vision is an innovative ultrasonic (UT) weld inspection system from General Electric Co. that allows specialists to collect accurate pipe weld inspection data. It mentions that National Instruments (NI) Corp. has launched two products such as NI 9792 and NI WSN-3226, which extend the communication and measurement capabilities of NI WSN platform.

Many non-destructive inspections for cracks rely on detecting ultrasound scattered or reflected from the crack. Recently, several methods for second-layer ultrasonic crack detection have been developed, sometimes using automated analysis methods to interpret the complex ultrasonic responses from multiple layers. In the validation of these techniques, the assumption is often made that fatigue cracks will reflect as much ultrasound as an artificially introduced EDM notch or saw cut. However, this is not always the case for ‘closed’ cracks, which can have a very low ultrasonic reflectivity. Of particular concern is the case of cold-worked holes, where a residual compressive stress field exists, extending to approximately one radius from the fastener hole. In addition, if a crack has grown under fatigue loads that include high peak stresses, there can be a closed region in the plastic zone at the crack tip. To complicate matters further, interference-fit fasteners apply an additional tensile stress, which may or may not counteract the cold-worked stress field near to the fastener, depending on the amount of interference. This problem was encountered whilst validating a two-layer ultrasonic inspection technique on real cracks in a real fatigue-test wing containing cold-worked holes. Inspections were performed at four different remote load levels by stress-jacking the wing. Whilst the ultrasonic indications from some of the cracks grew with increasing remote load, others did not. Some ultrasonic indications grew both towards the fastener and away from it, suggesting that both crack-tip closure and cold-worked crack-root closure were occurring. A possible reason for some cracks not growing is that they were already being held open by interference-fit fasteners. The aim of this project was to investigate and understand the effects of cold working, interference-fit fasteners and crack-tip closure on the ultrasonic detectability and sizing of cracks. In particular, information was required about the potential improvement in defect detectability by applying a remote tensile load to the structure to overcome the residual compressive stresses. Results will be reported of an experiment designed to grow fatigue cracks to a range of lengths at cold-worked holes in a single specimen, with interference-fit fasteners installed. These cracks could then be inspected ultrasonically at various remote tensile-load levels and the results compared with EDM notches in a similar specimen. Finally, the interference-fit fasteners could be removed and the ultrasonic inspections at the various loads repeated. Initial results have confirmed that ultrasonic indication size and amplitude both increase with remote tensile load but further results will be required to determine the dependence of defect detectability on remote load. [ABSTRACT FROM AUTHOR]

An ultrasonic system that enables the measurement of paper properties like anisotropy or filler content is fully described in this paper. The system is composed of a measuring head that integrates 16 ultrasonic bimorph circumferentially disposed transducers. The hardware responsible for the emission and the reception tasks is PC controlled by means of an acquisition board and by specifically developed software. The experimental results obtained present a very good agreement with others obtained by classic methods, namely destructive tests, and allow evaluation of paper properties such as tensile stiffness index, tensile stiffness orientation angle, anisotropy and filler content, with good accuracy. [ABSTRACT FROM AUTHOR]

Over the years British Energy, in collaboration with British Nuclear Group, has developed an extensive suite of computer codes for modelling the ultrasonic inspection of smooth and rough planar defects in ferritic steel components. The models are used to help in the design of new inspections, and to provide evidence on detection capability when writing a technical justification for inspection qualification purposes. This paper provides an update on the current status of these models, including their experimental validation. It also briefly describes some recent developments in modelling the scattering from rough defects, allowing for the effects of fine-scale roughness, and in modelling the inspection of surface-breaking cracks using the corner effect. In both cases, experimental validation plays an important role. A recent application of the models, in the technical justification of an automated ultrasonic in-service inspection of a pressuriser weld at Sizewell B Power Station, is also described. [ABSTRACT FROM AUTHOR]

Laser-Air Hybrid Ultrasonic Technique (LAHUT) combines laser generation with air-coupled detection of ultrasound. The technique is non-contact and has the characteristic of operating from remote distances. Acoustic wave lasergeneration apparatus can be metres away from the interrogated surface while air-coupled detection standoff can be on the order of several centimetres. The technique has the unique capability of interrogating structural materials in their true industrial environment. Dynamic tests are performed on parts with complex geometry, limited accessibility and curved surfaces. Also, dark and rough finish surfaces, which significantly reduce the efficiency of optical detection techniques, can be interrogated successfully. These characteristics make the LAHUT ideal for many industrial applications including the railroad industry. It was developed for railroad inspections targeting the most critical cracks in rails and wheels. State-of-the-art inspection techniques available to the railroad industry often miss Vertical Split Head (VVSH) and Transverse Detail Defect (TDD), which lie in unfavourable positions and orientations in the rail head. No method exists to perform dynamic inspections of the rail base or any part of the railroad wheel. Laboratory experiments were performed for the detection of TDD and Proof Of Concept (POC) field tests were performed for VSH, rail base cracks, thermal fatigue cracks along the wheel flange and tread and subsurface Shattered Rim Cracks (SRC) along the wheel tread. The results were successful and highly repeatable. The technique lends itself for digital collection and automated processing of data making the LAHUT a very strong candidate for next-generation railroad inspection tzechnique. [ABSTRACT FROM AUTHOR]

Periodic inspection of railway axles is carried out to avoid axle failures. Analytical methods for determining the periodicity of inspection require knowledge of load conditions, materials properties and inspection reliability. The Wheelset Integrated Design and Maintenance (WIDEM) Project is being carried out to acquire some of this data and to develop methodologies for axle design. An example is given in this paper of the measurement of inspection reliability from a set of 11 cracked axles. The method estimates the POD of the in-situ inspection technique from the response versus size method, the size in this case being measured with Alternating Current Potential Drop (ACPD), phased array ultrasonics and time-of-flight diffraction. The results show that useful information is generated by such methods and a further experiment is planned on a different range of axles to obtain wider applicability of the data obtained. [ABSTRACT FROM AUTHOR]

Advanced non-destructive techniques integrate ultrasonic arrays with array controllers that perform full waveform capture (FWC). FWC is the term used to describe the acquisition of RF waveforms corresponding to specific transmit-receive beams from an array. With FWC, the full waveform is available for post-processing. However, FWC only allows rectification and gating during data acquisition and post-processing. If the correct information is not acquired the first time, inspection cost and time may be compromised. FRD (full raw data) collection works similarly to FWC, acquiring the time-domain responses from the excited phased array transmit-receive combinations. However, the transmit and receive apertures for FRD are much smaller than for FWC – typically one element each – and there are many receive locations for each transmit location. The main advantages of FRD collection are the facility for real-time imaging and to optimise features such as beam steering, aperture shading and focusing during the post-processing stage. Compounding, a technique previously used for biomedical applications, has the potential to be applied as a novel technique in NDT. Incoherent compounding is a signal processing technique that involves recombination of echoes from different propagation paths. Incoherent compounding only considers the amplitude information from received signals. Therefore, the interpretation of received signals is simplified. A favourable application of this technique is crack sizing. Coherent processing, in which the amplitude and phase of received signals are considered, would be beneficial when enhanced resolution is necessary. Both techniques would be applicable to multi-layered structures commonly found within the aerospace industry. Experimentally, using a B-scan, incoherent compounding can be demonstrated by mirroring the direct image onto the reflected image. This paper will discuss incoherent compounding using a linear phased array probe with FRD capture as an innovative post-processing method. Furthermore, the results confirm the sizing and location of a combination of side-drilled holes that mimic defects. [ABSTRACT FROM AUTHOR]

Conventional ultrasonic array technology has limitations associated with detection and sizing of defects, particularly for difficult structures such as the carbon fibre composites and titanium composites used widely for construction of aircraft components. This paper describes an investigation of data acquisition and signal processing techniques for crack sizing using electronically-scanned ultrasonic linear arrays. The data acquisition technique involves aperture number variance (that is, varying the number of active elements on the array) and the use of full raw data (FRD) capture. FRD capture accumulates the time domain responses from each transmitter-receiver pair manipulated on the array. With FRD capture, the raw data is collected from the array probe and reconstructed to produce a real-time image during the scan. However, the full data set is also stored and so beam steering and focusing become features of post-processing analysis. Experimental results obtained from an ultrasonic array inspection of difficult materials with and without FRD capture are compared for detection capability and precision of simulated crack sizing. A detailed description of the distributed data acquisition system has been described previously. [ABSTRACT FROM AUTHOR]

The use of ultrasonic array transducers for NDT is growing rapidly, as commercial array controllers become more widely available. However, conventional 1D array designs limit the flexibility of such systems, for example, making it impossible to skew the beam on curved surfaces. As 2D arrays allow 3D beam steering, they are thus of major interest. However, the use of conventional excitation voltages, typically 200 V, with the many elements in 2D arrays may be inconvenient, making investigation of low-voltage operation worthwhile. The work reported here relates to array design for low-voltage operation for NDT. A 1D array was first produced, operating at approximately 1.5 MHz. This was based on a piezocomposite plate made with PZT 5A ceramic and epoxy resin. The plate was bonded to a PCB whose copper tracks defined the array elements, 10 mm long, 0.28 mm wide, and with edge-to-edge separation of 0.4 mm. The device was excited with a standard logic voltage of 3.3 V on a 75 mm-thick aluminium block. The pulse-echo insertion loss, using a signal reflected from the back wall of the aluminium, was found to be 59 dB. A 2D ultrasonic array has also been produced, with 16 elements in a 4 x 4 matrix, using the same piezocomposite material. In this case, the element size is 1.2 mm × 1.2 mm, and the edge-to-edge separation is 0.4 mm. In tests with 3.3 V peak-to-peak excitation voltage, the insertion loss was found to be 73 dB. The results suggest that arrays made with monolithic piezocomposite material have better performance for NDT than previous arrays made with monolithic ceramic and that low-voltage excitation will be viable in practice, with low noise amplification and appropriate signal processing. [ABSTRACT FROM AUTHOR]

Development of ultrasonic non-destructive testing (NDT) techniques has involved a combination of both simulation and experimental methods. This paper describes a numerical simulation and imaging technique, which incorporates direct, mixed and specular reflections from the internal defects. The NDT simulation algorithm is based on an extended diffraction model of the ultrasonic transducer. The B-scan image correction method has been developed taking into account the angle of the transducer wedge and specular reflections. The most typical defect orientation cases were analysed. An aluminium test sample with side drilled holes was analysed using computer based simulation and experimentally. The comparison of the results has shown good correspondence. A simulation of V-weld inspection was also carried out. [ABSTRACT FROM AUTHOR]

Presents a non-destructive ultrasonic investigation of a group of 15 line insulators of LP 75/17 type in Great Britain. Degradation process of insulator ceramics; Fundamentals of ultrasonic control; Ultrasonic measuring set-up.

A design of an ultrasonic apparatus for testing material samples is presented. It is based on a pulse-echo technique and involves wave reflection and refraction at a liquid-solid interface. The main part of the apparatus is a transducer-cell, which holds the sample under test (SUT). The novelty of the design resides in the use of prism-shaped specimens and the special configuration of the transducer cell, that allows for the simple generation of both longitudinal and shear waves within the material using just one transducer. Wave velocities are derived from a special formula, which represents a significant improvement over an earlier version of the apparatus designed by the author. [ABSTRACT FROM AUTHOR]

The article evaluates several products including the FAG Wear Debris Monitor from Schaeffler (UK) Ltd., SpectrolineR FC-150 ultra-high-intensity ultraviolet (UV) inspection lamp from Spectronics Corp., and USM Vision innovative ultrasonic (UT) weld inspection system from GE Sensing & Inspection Technologies GmbH.

The article discusses various reports published within the issue including the Annual Conference of The British Institute of Non-Destructive Testing, articles that feature developments in ultrasonic technology, and papers that look at ways to speed up the processing of full matrix capture data.

The article reports on a contract awarded to KTN Belgium NV to inspect 35,000 pipe, reactor and vessel locations at an oil refinery near Antwerp, for which the company rented 20 portable ultrasonic inspection instruments from Ashtead Technology to support their own equipment.

The article evaluates several products including the SuperXenon battery from Labino AB, P-Scan Stack System from the company, FORCE Technology, and VJT XQuik from VJ Technologies Inc.

The article reports that distribution service RSL NDT has been announced as the exclusive distributor partner for Sonatest involved in distribution of its conventional and advanced ultrasonic products in Scotland; and mentions that the products include the D Series UT Flaw Detectors.

The article reports that the global market for ultrasonic equipment reached 54.5 billion dollars by 2021.

The article focuses on market research reports from market researcher Research and Market revealing growth in nondestructive testing (NDT) and condition monitoring (CM) market, forecast of growth in the industrial radiography equipment sector, and attempts for various types of ultrasonic products.

This article describes the term calibration block and reference block. Calibration block is defined in British Standard BS2704 as a piece of material of specified composition, heat treatment, geometric form, and surface finish, by means of which ultrasonic equipment can be assessed and calibrated for the examination of material of the same general composition. Therefore, a calibration block may be a simple step wedge in a particular material to allow the timebase to be calibrated for accurate thickness measurement, or it may be a more complex block like the A.2 block described in BS 2704 which allows calibration of timebase, plus calibration of probe index, angle, and resolution. Reference block is defined in BS2704 as an aid to interpretation in the form of a test piece of the same material, significant dimensions and shape as a particular object under examination, but not necessarily containing natural or artificial defects.

Reviews several scientific apparatus and instruments. Details of the ultrasonic corrosion gauges developed by Panametrics-NDT Inc.; Features of the NOVA industrial X-ray film processor by GE Inspection Technologies; Functions of the DL750 ScopeCorder waveform measuring instrument manufactured by Yokogawa.

The article discusses the annual calibration requirements to be accomplished every end of the year for ensuring quality assurance, and mentions topics including the calibration of non-destructive testing (NDT) equipment, magnetic particle equipment, and advanced ultrasonic equipment.