Laboratory testing of the precision and accuracy of the TM-71 dilatometer

0499833 - ÚSMH 2019 RIV BG eng C - Konferenční příspěvek (zahraniční konf.)
Balek, Jan - Urban, R. - Štroner, M.
Laboratory testing of the precision and accuracy of the TM-71 dilatometer.
International Multidisciplinary Scientific GeoConference Surveying Geology and Mining Ecology Management, SGEM 2018. Vol. 18, Issue 1.2. Sofia: STEF92 Technology, 2018, s. 433-439. ISBN 978-619-7408-36-2. ISSN 1314-2704.
[International Multidisciplinary Scientific Geoconference, SGEM 2018 /18./. Albena (BG), 02.06.2018-08.06.2018]
Grant CEP: GA MŠMT(CZ) LM2015079
Institucionální podpora: RVO:67985891
Klíčová slova: TM-71 * laboratory * test * dilatometer * moire * accuracy * precision
Obor OECD: Environmental and geological engineering, geotechnics
https://www.sgem.org/sgemlib/spip.php?article11786

The TM-71 dilatometer is a device manufactured in the 60s of the 20th century in the Institute of Rock Structure and Mechanics of the Czech Academy of Sciences. It has been developed as a reliable and easy-to-use rock crack monitoring facility capable of working even in the least favorable climatic conditions. It is a purely mechanical system capable of determining relative shifts and rotations in all three axis of two monitored blocks. The device is read out using two pairs of overlapping optical patterns, which are firmly connected to the rock blocks. Their mutual shifts and rotations changes the structure of image emerging on the overlap of the patterns based on moiré effect. The device is currently widely used to study geodynamic processes such as slow slope movements or movements on fracture structures. This article describes laboratory testing of the TM-71 device to determine the precision and accuracy, which is essential for reliable evaluation of the data measured. At present, the accuracy of reading the instrument is well known, which directly depends on the properties of the moiré patterns used and is readily quantifiable by the mathematical way. The purpose of the instrument testing was primarily to determine the accuracy from the mechanical point of view. Namely, accuracy of the response of the optical patterns to the induced displacement of the monitored blocks. For several series of laboratory tests, standard deviations of measured displacements were determined.
Trvalý link: http://hdl.handle.net/11104/0292027