Portable BΔ-12HΦM and BΔ-12HΦΠ eddy-current flaw detectors

The scope of application, specific features of design and operation, and the main technical characteristics of portable BΔ-12HΦM and BΔ-12HΦΠ eddy-current flaw detectors are considered.     

The ТЛ-1МП Thickness Meter for Galvanic Coatings

The specifics for monitoring the thickness of electrically- conductive coatings on a conductive substrate are described. Difficulties involved in designing thickness meters that assist in this task are noted. The technical characteristics and design of a -1 versatile eddy-current sensor are presented.     

Silica-air double-clad optical fiber

A new design of the silica-air double-clad optical fiber is proposed. The fiber was prepared from an MCVD preform inserted into a supporting silica tube with a fluorine-doped connective element with a lower refractive index (Δn~-4×10^-3) and air as the second cladding. A numerical aperture as high as 0.3 was measured for the first cladding and for fiber lengths up to 50 cm. Although it is realized that the results are preliminary, the optimization of the fiber parameters promises a new all-glass design for double-clad optical fibers for high-power fiber laser applications     

VE-26NP Eddy-Current Structuroscope

The destination and technical characteristics of a VE-26NP eddy-current structuroscope are described. The domains of application and characteristics of the VE-26NP eddy-current structuroscope are presented. The question of the necessity for presorting on the basis of the specific electrical conductivity is considered. The possibilities of using the VE-26NP eddy-current structuroscope for nondestructive testing of the quality of heat treatment of products from nonmagnetic alloys are analyzed. Examples of testing the specific electrical conductivity of thin-wall objects are given.     

Technique for continuous tuning of optical fiber lasers

For the first time to the authors' knowledge, we have demonstrated how thermally controlled overcoupled fused fiber couplers and fiber loop mirrors based on these couplers can be used as broadband tuning elements in a fiber laser cavity. No bulk optical elements play any role in this technique. Temperature tuning the coupler results in a shift in the coupling ratio or in the effective output coupler transmission. For a fixed pump source, and for a given laser cavity, this shift causes the lasing wavelength to shift. We have continuously tuned an Er silica fiber laser in this manner over the range of 1527-1570 nm in a ring configuration, and, using a fiber loop mirror with these couplers in a linear Tm silica fiber laser cavity, we have achieved more than 50-nm broadband tuning over the range of 1850-1910 nm. The tuning range and the sensitivity to temperature depend on the degree of overcoupling of the loop mirror coupler.     

Tunable thulium-doped all-fiber laser

We demonstrate a tunable thulium-doped fiber ring laser wherein a single fused coupler acts simultaneously as the wavelength-division multiplexing for pump radiation, a lasing wavelength selective element, and output mirror. Temperature tuning of up to 2 nm/°C over a range of 40 nm and polarization tuning of over 100 nm within the spectral range from 1810 to 1930 nm have been obtained     

Eddy-Current Testing of the Quality of Railway Wheels

The dependence of the minimum size of a detected flaw on the probe diameter and the operating gap has been derived and practically approved on a new automated line for testing the quality of railway wheels.__________Translated from Defektoskopiya, Vol. 41, No. 3, 2005, pp. 74–78.Original Russian Text Copyright © 2005 by Shubochkin.     

A Modern Solution to Problems of Eddy-Current Structuroscopy

The problems arising during nondestructive quality tests of articles of nonmagnetic alloys and during sorting in the electrical conductivity are considered. The function and performance characteristics of a -26 eddy-current structruroscope are described. The structural diagram of this device and the algorithm of its operation are described. The capabilities of the -26 eddy-current structruroscope for performing nondestructive quality tests of thermal treatment of articles made of nonmagnetic materials are analyzed.