The Wild NA3000 precise digital level with serial number 91053 was evaluated for temperature dependent errors and the instrument's precision in double-run line levelling.
A computer-instrument interface program (NA3K) was developed to remotely operate the Wild NA3000 digital level from a personal computer.
The instrument tested was found to have a standard deviation of 1 km double-run line levelling (after DIN 18723 Part 2) of 0.34 mm per square-root kilometre. This value certainly classes the Wild NA3000 as a precise levelling instrument.
The change of the collimation error with temperature was investigated. A value of -0.392"/°C was determined for the temperature range from 21.6°C to 45.3°C. This value is smaller than, and of opposite sign to, the values found by other researchers conducting similar experiments. The collimation error changed by +0.248"/°C in the temperature range from -11.5°C to 21.2°C. Previously published results are of the same sign but of larger value.
Vertical shifts in the line of sight
of the instrument of about +0.003 mm/°C were also detected. These vertical
shifts are at least partly due to the expansion of the body of the instrument
and its footscrews with temperature.
Back to Research HomePage
Last modified: 10/15/2001 by EGM