DBPapers

LEVELLING STAVES COMPARATOR ON THE BASIS OF INCREMENTAL MEASURING SYSTEM

AUTHOR/S: D. BARKOVIC, M. ZRINJSKI, T. DEBELJAK
Sunday 1 August 2010 by Libadmin2008

8th International Scientific Conference - SGEM2008, www.sgem.org, SGEM2008 Conference Proceedings/ ISBN: 954-918181-2, June 16-20, 2008, Vol. 2, 509-516 pp

ABSTRACT

Modern technology in the production of geodetic instruments and accessories needed
for measuring basic quantities (distance and angle) has reached high level. In the filed
of geometric levelling, colour layers are put on invar tapes very precisely with
measuring uncertainty of 10–50 μm. These tapes present working scale on invar
levelling staves. Using modern precise level (optical of digital) one can read the
smallest detail on invar levelling staff with measuring uncertainty of 0.01 mm. Hence, it
is obvious that in high accuracy levelling the invar tapes must be compared with the
standard of measuring uncertainty of a few micrometers because of the influence of
systematic errors of the levelling staff scale and its irregularly made scale. Although in
precise measurement of linear quantities the emphasis is given to laser interferometric
systems, the comparator with the standard on the basis of incremental measuring system
with the measuring uncertainty of U95% = 0.5 μm/m (Barković 2002). has been
constructed at the Faculty of Geodesy, University of Zagreb. We have decided to use
this method primarily because of its high accuracy, simplicity and economic efficiency.
This paper presents the comparator of levelling staves developed in the Laboratory for
measurements and measuring techniques at the Faculty of Geodesy, University of
Zagreb. The comparison procedure has been described and the report on comparison
presented the comparison accuracy estimation is visible.

Keywords: comparator, levelling staves, incremental measuring system, measuring uncertainty.