Holographic techniques for nondestructive testing of tires. Interim report.

Mode of access: Internet.

Diagnostic motor vehicle inspection demonstration projects, program engineering support. Volume 2 - appendix A: evaluation of the measurement performance of inspection equipment in the five demonstration projects and in selected repair agencies. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Diagnostic motor vehicle inspection demonstration projects, program engineering support. Volume 9 - appendix H: vehicle designs that facilitate or hinder inspection and repair and interchangeability and interface capability of test equipment and vehicles. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Passenger vehicle tire inspection equipment service manual, operation and maintenance. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Application study of ultrasonic nondestructive inspection for tire compliance testing. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Passenger vehicle tire inspection equipment - volume I: summary. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Passenger vehicle tire inspection equipment - volume II: technical report. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

Dynamic force balances for short-duration hypersonic testing facilities

Two force balance techniques for use in hypersonic impulse facilities are compared by measuring the drag force on a 30° semi-apex-angle blunt cone model in a hypersonic shock tunnel at a free stream Mach number of 5.75. An accelerometer-based balance and a stress-wave force balance were tested simultaneously on the same model to measure the drag force. It was found that drag force measurements could be made using both techniques in a flow with a 450-μ s test period. The measured drag forces compared well with the theoretical values estimated using Newtonian theory.

User dyads in software testing: bypassing the need for expert observers

This paper arises out of a research study into the online help facilities provided in popular software applications such as word processors. Its particular focus is on experimental methods of evaluating the effectiveness and usability of those facilities. Focus groups, questionnaires, and online surveys had already been used in other phases of the study, but it was judged that these approaches would be unsuitable for measuring effectiveness and usability because they are susceptible to respondents' subjectivity. Direct observation of people working on set word-processing tasks was ruled out initially because of a lack of trained observers; it would have taken too long for the investigator to observe a large enough sample by himself. Automatic recording of users' actions was also rejected, as it would have demanded equipment and/or software that was not available and seemed too expensive to acquire. The approach and techniques described here were an attempt to overcome these difficulties by using observers drawn from the same population of students that provided the test subjects; as a by-product, this may also have enhanced the acceptability (and hence possibly the validity) of the experiments by reducing the exam pressure perceived by participants.

Vibrational methods applied to NDT testing and fluid density measurement

A system for the NDI' testing of the integrity of conposite materials and of adhesive bonds has been developed to meet industrial requirements. The vibration techniques used were found to be applicable to the development of fluid measuring transducers. The vibrational spectra of thin rectangular bars were used for the NDT work. A machined cut in a bar had a significant effect on the spectrum but a genuine crack gave an unambiguous response at high amplitudes. This was the generation of fretting crack noise at frequencies far above that of the drive. A specially designed vibrational decrement meter which, in effect, measures mechanical energy loss enabled a numerical classification of material adhesion to be obtained. This was used to study bars which had been flame or plasma sprayed with a variety of materials. It has become a useful tool in optimising coating methods. A direct industrial application was to classify piston rings of high performance I.C. engines. Each consists of a cast iron ring with a channel into which molybdenum, a good bearing surface, is sprayed. The NDT classification agreed quite well with the destructive test normally used. The techniques and equipment used for the NOT work were applied to the development of the tuning fork transducers investigated by Hassan into commercial density and viscosity devices. Using narrowly spaced, large area tines a thin lamina of fluid is trapped between them. It stores a large fraction of the vibrational energy which, acting as an inertia load reduces the frequency. Magnetostrictive and piezoelectric effects together or in combination enable the fork to be operated through a flange. This allows it to be used in pipeline or 'dipstick' applications. Using a different tine geometry the viscosity loading can be predoninant. This as well as the signal decrement of the density transducer makes a practical viscometer.

'Urine testing is a waste of time': newly diagnosed Type 2 diabetes patients' perceptions of self-monitoring

Aims To date, there is no convincing evidence that non-insulin treated patients who undertake self-blood glucose monitoring (SBGM) have better glycaemic control than those who test their urine. This has led to a recommendation that non-insulin dependent patients undertake urine testing, which is the cheaper option. This recommendation does not take account of patients' experiences and views. This study explores the respective merits of urine testing and SBGM from the perspectives of newly diagnosed patients with Type 2 diabetes. Methods Qualitative study using repeat in-depth interviews with 40 patients. Patients were interviewed three times at 6-monthly intervals over 1 year. Patients were recruited from hospital clinics and general practices in Lothian, Scotland. The study was informed by grounded theory, which involves concurrent data collection and analysis. Results Patients reported strongly negative views of urine testing, particularly when they compared it with SBGM. Patients perceived urine testing as less convenient, less hygienic and less accurate than SBGM. Most patients assumed that blood glucose meters were given to those with a more advanced or serious form of diabetes. This could have implications for how they thought about their own disease. Patients often interpreted negative urine results as indicating that they could not have diabetes. Conclusions Professionals should be aware of the meanings and understandings patients attach to the receipt and use of different types of self-monitoring equipment. Guidelines that promote the use of consistent criteria for equipment allocation are required. The manner in which negative urine results are conveyed needs to be reconsidered.

Application of digital image processing techniques to the photometric testing of vehicle headlamps

The aim of this Interdisciplinary Higher Degrees project was the development of a high-speed method of photometrically testing vehicle headlamps, based on the use of image processing techniques, for Lucas Electrical Limited. Photometric testing involves measuring the illuminance produced by a lamp at certain points in its beam distribution. Headlamp performance is best represented by an iso-lux diagram, showing illuminance contours, produced from a two-dimensional array of data. Conventionally, the tens of thousands of measurements required are made using a single stationary photodetector and a two-dimensional mechanical scanning system which enables a lamp's horizontal and vertical orientation relative to the photodetector to be changed. Even using motorised scanning and computerised data-logging, the data acquisition time for a typical iso-lux test is about twenty minutes. A detailed study was made of the concept of using a video camera and a digital image processing system to scan and measure a lamp's beam without the need for the time-consuming mechanical movement. Although the concept was shown to be theoretically feasible, and a prototype system designed, it could not be implemented because of the technical limitations of commercially-available equipment. An alternative high-speed approach was developed, however, and a second prototype syqtem designed. The proposed arrangement again uses an image processing system, but in conjunction with a one-dimensional array of photodetectors and a one-dimensional mechanical scanning system in place of a video camera. This system can be implemented using commercially-available equipment and, although not entirely eliminating the need for mechanical movement, greatly reduces the amount required, resulting in a predicted data acquisiton time of about twenty seconds for a typical iso-lux test. As a consequence of the work undertaken, the company initiated an 80,000 programme to implement the system proposed by the author.

A heuristic algorithm to generate test program sequences for moving probe electronic test equipment

The electronics industry, is experiencing two trends one of which is the drive towards miniaturization of electronic products. The in-circuit testing predominantly used for continuity testing of printed circuit boards (PCB) can no longer meet the demands of smaller size circuits. This has lead to the development of moving probe testing equipment. Moving Probe Test opens up the opportunity to test PCBs where the test points are on a small pitch (distance between points). However, since the test uses probes that move sequentially to perform the test, the total test time is much greater than traditional in-circuit test. While significant effort has concentrated on the equipment design and development, little work has examined algorithms for efficient test sequencing. The test sequence has the greatest impact on total test time, which will determine the production cycle time of the product. Minimizing total test time is a NP-hard problem similar to the traveling salesman problem, except with two traveling salesmen that must coordinate their movements. The main goal of this thesis was to develop a heuristic algorithm to minimize the Flying Probe test time and evaluate the algorithm against a "Nearest Neighbor" algorithm. The algorithm was implemented with Visual Basic and MS Access database. The algorithm was evaluated with actual PCB test data taken from Industry. A statistical analysis with 95% C.C. was performed to test the hypothesis that the proposed algorithm finds a sequence which has a total test time less than the total test time found by the "Nearest Neighbor" approach. Findings demonstrated that the proposed heuristic algorithm reduces the total test time of the test and, therefore, production cycle time can be reduced through proper sequencing.

Equipment quality control

Mammography equipment must be evaluated to ensure that images will be of acceptable diagnostic quality with lowest radiation dose. Quality Assurance (QA) aims to provide systematic and constant improvement through a feedback mechanism to address the technical, clinical and training aspects. Quality Control (QC), in relation to mammography equipment, comprises a series of tests to determine equipment performance characteristics. The introduction of digital technologies promoted changes in QC tests and protocols and there are some tests that are specific for each manufacturer. Within each country specifi c QC tests should be compliant with regulatory requirements and guidance. Ideally, one mammography practitioner should take overarching responsibility for QC within a service, with all practitioners having responsibility for actual QC testing. All QC results must be documented to facilitate troubleshooting, internal audit and external assessment. Generally speaking, the practitioner’s role includes performing, interpreting and recording the QC tests as well as reporting any out of action limits to their service lead. They must undertake additional continuous professional development to maintain their QC competencies. They are usually supported by technicians and medical physicists; in some countries the latter are mandatory. Technicians and/or medical physicists often perform many of the tests indicated within this chapter. It is important to recognise that this chapter is an attempt to encompass the main tests performed within European countries. Specific tests related to the service that you work within must be familiarised with and adhered too.