Development of high-temperature strain gages

Abstract

The functions of the National Bureau of Standards are set forth in the Act of Congress, March 3, 1901, as amended by Congress in Public Law 619, 1950. These include the development and maintenance of the national standards of measurement and the provision of means and methods for making measurements consistent with these standards; the determination of physical constants; and properties of materials; the development of methods and instruments for testing materials, devices, and structures; advisory services to government agencies on scientific and technical problems; inven tion and development of devices to serve special needs of the Government; and the development of standard practices, codes, and specifications. The work includes baric and applied research, develop ment, engineering, instrumentation, testing, evaluation, calibration services, and various consultation and information services. Research projects are also performed for other government agencies when the work relates to and supplements the basic program of the Bureau or when the Bureau's unique competence is required. The scope of activities is suggested by the listing of divisions and sections on the inside of the back cover, PublicationsThe results of the Bureau's work take the form of either actual equipment and devices or pub lished papers. These papers appear either in the Bureau's own series of publications or in the journals of professional and scientific societies* Hie Bureau itself publishes three periodicals available from the Government Printing Office: The Journal of Research, published in four separate sections, presents complete scientific and technical papers; the Technical News Bulletin presents summary and preliminary reports on work in progress; and Baric Radio Propagation Predictions provides data for determining the best frequencies to use for radio communications throughout the world. ForewordReliable data on the mechanical properties of structural materials at high temperatures are of critical importance in the development of aircraft engines, aircraft and missile frames subject to aerodynamic heating, and certain types of nuclear reactors. The measurement of strain in such structures not only pro vides the engineer with knowledge of the performance characteristics of the structure, but also gives information for improving the design.This Monograph summarizes work done at the National Bureau of Stand ards in a research program aimed at the development of new types of strain gages for high-temperature use. Sponsored by the Navy and the Air Force, the program has included an investigation of the properties of high-temperature strain-gage materials, the development of high-temperature strain gages, and the development and evaluation of high-temperature strain-gage cements.In discussing properties of strain-gage materials, it has been necessary to use proprietary names in referring to some of these materials. However, it should be understood that the Bureau does not recommend nor endorse any of the proprietary products mentioned...

Techniques and Materials for Optical Fiber Sensors Sealing in Dynamic Environments with High Pressure and High Temperature

“…These types of cement have been used for many years for general high-temperature research, electronics, metallurgical, nuclear, and industrial applications. Ceramic cement is commonly applied for strain gauge applications [ 15 , 16 ] and it has been reported in previous applications for FBG sensors [ 17 ]. Some of the characteristics of ceramic cement are its resistance to temperatures over 700 °C, oil, solvents, and most acids; it is heat conductive, thermal shock resistant and is an electrical insulator, it adheres to metals, ceramics, glass, porcelain, and most other surfaces and has excellent mechanical bonding characteristics.…”