Introducing a small scratch (10 - 25 (mu) depth) on the surface of a part containing residual stresses produces a small change in displacements around of the scratch on the surface. When the displacements are measured as a function of the depth of a scratch, a very small depth releases displacements of about (lambda) /10. The present paper shows that introduction of an additional faze shift permits determination of very small displacements and also presents the portable interferometer and the technique for measurement of residual stress in field conditions.

A new fiber-optic system for remote monitoring of explosive gases is described. The methodical and engineering aspects of developing a small-size instrument ((lambda) equals 1666 nm) with a multipass cell and a diffraction-focusing spectral divider based on using a differential absorption- spectroscopy method are considered.

Wall thinning in utility boiler waterwall tubing is a significant inspection concern for boiler operators. Historically, conventional ultrasonics has been used for inspection of these tubes. This technique has proved to be very labor intensive and slow. This has resulted in a `spot check' approach to inspections, making thickness measurements over a relatively small percentage of the total boiler wall area. NASA Langley Research Center has developed a thermal NDE technique designed to image and quantitatively characterize the amount of material thinning present in steel tubing. The technique involves the movement of a thermal line source across the outer surface of the tubing followed by an infrared imager at a fixed distance behind the line source. Quantitative images of the material loss due to corrosion are reconstructed from measurements of the induced surface temperature variations. This paper will present a discussion of the development of the thermal imaging system as well as the techniques used to reconstruct images of flaws. The application of the thermal line source, coupled with this analysis technique, represents a significant improvement in the inspection speed for large structures such as boiler waterwalls while still providing high-resolution thickness measurements. A theoretical basis for the technique will be presented thus demonstrating the quantitative nature of the technique. Further, results of laboratory experiments on flat panel specimens with fabricated material loss regions will be presented to demonstrate the capabilities of the technique. Additionally, the results of applying this technology to actual waterwall tubing samples will be presented.

A measurement method and a portable microspectrophotometer are developed. The instrument enables to solve a problem of registering the optical transmission spectra in a wide range of optical-density variations with a guaranteed preassigned absolute error.

In using the electric power lines (EPL), a major problem is the location of initiating the corona discharges causing high power losses and a failure of different EPL elements. A portable optoelectronic device for detecting the EPL faults by a method of remote measuring of their UV radiation is developed. The device detects a point corona discharge from a distance of 150 m. The detector is a monoblock and its service is provided by an operator.

The magnetostrictive sensor technique was used to generate and detect elastic guided waves in a steel pipe for ultrasonic pipe inspection. A notch with a fixed length but varied depths was made on the pipe to simulate a crack, and the reflection coefficients of the guided waves was used to characterize the notch depth. The group velocity of the guided wave propagating in the pipe measured by the magnetostrictive sensor was found to fit the calculated group velocity well. The frequency content of the guided waves in the pipe depends upon the center frequency of the electric pulse applied to the magnetostrictive sensor. For the center frequencies between 10 and 80 kHz, the reflection coefficient was found to have a minimal value when the notch area was 10 percent of the total cross-sectional area; but for the center frequencies between 100 and 200 kHz, the reflection coefficient was found to be a nearly linear function of the notch area.

In this paper we present the results of analytical study and experimental examination of long pipe oscillations. Two different approaches have been used for theoretical study, which are the Global Modal Analysis and direct solution of the wave equation for oscillating modes revealing and analysis of the displacement. The obtained results are compared with experimental data from pulse-laser holographic non-destructive testing of pipe vibration.

This paper analyzes the thermal and mechanical characteristic of CCD sensor used for monitoring the three thousand-meter pipes deep underground, and then, gives the method for computation and design of the protection system. The conclusions of computation are proved by experiment.

A set of investigations on determining the additional analytical signatures for remote methods of locating leakages in gas pipelines is carried out. As a result, the inclusion of a laser spectrometric channel as a component of a remote-detection equipment is substantiated. The laser spectrometric channel provides information on the presence of a WLHF (wide light-hydrocarbon fraction)--product in the atmospheric surface layer in a gas-pipeline area that increases the authenticity of a leakage location by TV--and thermal imaging channels of a helicopter equipment.

The paper generalizes the long-term Optooil's experience on optical method developments and a practical use of instrumental (portable and helicopter) monitoring facilities including those based on Raman scattering and differential absorption methods. The main characteristics of the instruments and results of their use at objects of the largest oil-pipeline transport enterprise in Russia, Open- End Joint-Stock Company Sibnefteprovod, are presented.

Most of oil product pipelines have a design life from 20 till 25 years. The first attributes of their destruction are leakage of oil products. In our paper we try to discuss advantages and disadvantages of one of the main nondestructive techniques to oil product pipelines testing-- lidar technologies and its application to leakage detection. We consider applications of two basical lidars--IR-cw--LFM lidar (DIAL-system) for methane determining and pulsed lidar based on YAG:Nd³⁺ laser for registration of liquid oil products fluoristation. Set-ups for both lidars were made in Tupolev Kazan State Technical University and were used on the area of Sredne-Volgsk TransNefteProduct oil company for pipelines testing. Theoretical considerations and experimental results are presented. Some technical problems of specified lidars and their decisions are discussed. Particularly we present two frequency technique for He-Ne-DIAL-system and peculiarities of pumping source with high repetition range for pulsed laser. Its allow to improve characteristics of lidars. Possibilities of computerized leak detection system based on two specified lidars are discussed. It is shown that system can analyze leakage of different oil products, can determine leakage location (the second function of lidars-laser locator), can evaluate degree of damages. The structure of system and its peculiarities are shown.

Most oil product pipelines have a design life from 20 till 25 years. The first attributes of their destruction are leakage of oil products. So it is necessary to test pipelines by means of leak detection systems. But most of main oil product pipelines are locating in the difficulty accessible places: deep forests, marsh lands and so on. One way to simplify delivery of testing systems to pipelines location is to use mobile leak detection systems. In our paper we try to discuss experience of creation of different mobile systems. In the base of each system stands either lidar system, or UHF thermography system, which are developed in the Kazan State Technical University. We present results of designing of four mobile systems. Two systems based on air vehicles. First one--on aerostat `Crimea' (SRI of Aeroelastic Systems) and second one--on programming shuttle airplace (Vizier Engineering, Inc.). Loading weight of this vehicles allow to transportate radiometric devices for UHF thermography. And two systems are based on land car vehicles--KAMAZ-4208 and UAZ-3962. First one-lidar integrated system for methane (IR-cw-LFM He- Ne-DIAL lidar) and liquid oil product detection (pulsed YAG:Nd³⁺ lidar) with MIC-2000 computer. Second one-- computerized system for UHF thermography with mapping possibilities. Theoretical considerations, system demands and practical results are discussed.

This paper presents an overview of the emerging field of predictive engineering. This is an integrated approach to life-cycle analysis, system monitoring, and management and usable-life prediction that is built on life assurance methodologies, measurements, data analysis and the application of predictive models applied to critical structures and systems. The science and technology that is now becoming predictive engineering has been developing over a period of nearly 30 years. Research is currently in progress to develop predictive engineering for application to critical defense infrastructure and systems, including units in the national conventional munitions stockpile, and to extend its application to elements in the critical national infrastructure.