Geometrical instruments – Distance measuring – Opposed contacts
Patent
1996-03-25
1997-12-23
Will, Thomas B.
Geometrical instruments
Distance measuring
Opposed contacts
73795, G01B 530
Patent
active
056996241
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a fluid-cooled extensometer for extension measurements preferably of hot test specimens and components; the application range lies between room temperature and about 2300.degree. C. with a preferred working range up to about 1800.degree. C. The extensometer in accordance with the invention can be employed under normal pressure as well as in high vacuum, and it is also possible to use it in the above-atmospheric pressure range. Normally the high-termperature extensometer in accordance with the invention is employed in an air atmosphere. However, it can also be used in any desired gaseous media, though in the case of corrosive or aggressive media the material chosen must have the appropriate characteristics. It is a fundamental feature of the invention that the extension measurements are possible regardless of relative movements of the specimen to be tested in the mm range; i.e., if such relative movements of the test specimen should occur during the measurement process, they are compensated inherently in all three spatial coordinates.
The previous state of the art is characterized by extensometers that do not perform this compensation. Furthermore, the previous extensometers do not ensure the high measurement accuracy, especially in the temperature ranges between about 1500.degree. C. and 1800.degree. C. Nor has it previously been possible to position the tips of the measurement probes with such precise reproducibility. In addition, the results of measurements with extensometers of the previous construction, apart from expensive special designs, are dependent on the atmospheric pressure.
SUMMARY OF THE INVENTION
It is therefore the object of the invention to provide an extensometer that compensates any movements of the test specimen in the mm range that may occur during the measurement process in all three spatial coordinates, that produces measurement results independent of the temperature of the test specimen up to about 1800.degree. C. and of the ambient temperature up to about 150.degree. C., and that enables exact, reproducible positioning of the probe tip.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a schematic view of a high temperature extensometer according to the invention;
FIG. 2 is a sectional view along section line C--C of FIG. 1;
FIG. 3 is a sectional view along section line A--A of FIG. 1;
FIG. 4 is a sectional view along section line B--B of FIG. 1; and
FIG. 5 is a sectional view along section line D--D of FIG. 1.
DETAILED DESCRIPTION
The two measurement probes 14, the tips of which make contact with the test specimen 15 (FIG. 1), are biaxially suspended on a gimbal mount in the frames 3, 4 and 5 (FIG. 2). In order to obtain relative movements of the two probes 14 only in a specified measurement direction X within the movement plane, or to permit such movements only there, each probe 14 is in turn independently gimbal-mounted within the frame 4 (FIG. 2). The outer frame 3 of the gimbal system is connected to a base plate 1 by a linear guide mechanism, here in the form of two shafts 10 arranged so that the frame 3 can slide on the shafts 10 in the long direction Z of the measurement apparatus (FIG. 3 and FIG. 5). Other linear guide means for the frame 3 are also possible, e.g. rollers. Two cylindrical pressure springs 16 press the frame 3 and hence the whole gimbal suspension including the probes 14 in the resting state, by way of the block 6, against the adjustable stop bolts 17, which are screwed into the stopping block 7. Independently thereof, the initial length l.sub.o (FIG. 1) in the resting state is adjusted by way of two additional stop bolts 18 and the stopping block 7. The probes 14 are likewise clamped by stop bolts 18 in the stopping block 7 and thereby fixed. In order to make the baseline length for the measurement l.sub.o in FIG. 1) variable in principle, exchangeable clamping devices 20 with smaller or larger bases are also provided.
When the extensometer is moved into contact with the test specimen, displacement o
REFERENCES:
patent: 2588630 (1952-03-01), Jackman
patent: 4884456 (1989-12-01), Meline et al.
patent: 5015825 (1991-05-01), Brindley
patent: 5083465 (1992-01-01), Myers
patent: 5123175 (1992-06-01), Van Der Kuur
Liu, et al., "Uniaxial Tensile Strain Measurement for Ceramic Testing at Elevated Temperatures: Requirements, Problems, and Solutions", International Journal of High Technology Ceramics, Bd. 4, 1988, pp. 161-179. No month.
Quesnel, et al., "Extensometer extender for conversion of room-temperature extensometers for high-temperature applications", Review of Scientific Instruments, Bd. 54, Nr. 2, Feb. 1983, NY, US, pp. 226-228.
Rohrbach, "Handbuch fur experimentelle Spannungsanalyse", VDI-Verlag GmbH, 1989, pp. 560-565. No month.
Gaus Rainer
Gesell Gunther
Zauner Stefan
Industrieanlagen-Betriebsgesellschaft mbH
Will Thomas B.
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