17. CHECK AND ADJUSTMENT
17-1
17. CHECK AND ADJUSTMENT
17.1 Checking Accuracy of the Distance Measurement
Normally, the instrument constant does not have discrepancy. It is recommended you measure
and compare with an accurately measured distance at a location where the precision is specifically
monitored on a consistent basis. If such a location is not available, establish your own base line
over 20m (when purchasing the instrument) and compare with the data measured with newly
purchased instrument.
In both cases note that the setup displacement of the instrument position over the point), the
prism, baseline precision, poor collimation, atmospheric correction, and correction for refraction
and earth curvature determine the inspection precision. Please keep in mind these points.
Also, when providing a base line in a building, please note that the difference in temperature greatly
changes the length measured in the building.
If a difference of 5mm or over is the result from the comparative measurement, the following
procedure as shown below could be used to change the instrument constant.
Provide point C on a straight line, connecting straight line AB which is almost horizontal and
about 100m long, and measure straight lines AB, AC and BC.
Obtain the instrument constant by repeating
above several times.
Instrument
constant=AC+BC-AB
When there is error between written instrument constant value and calculated value, review
the Chapter 17.4 "How to set the instrument constant" procedure. The instrument constant
value set at shipping time is attached on label at the bottom of the AP-L1A .
Once again, measure at a calibrated baseline and compare with AP-L1A baseline length.
If using above procedure and no difference is found from the instrument constant at the
factory or a difference of over 5mm is found, contact TOPCON or your TOPCON dealer.
A
C
B
Summary of Contents for AP-L1A
Page 1: ...INSTRUCTION MANUAL AUTOMATIC TRACKING TOTAL STATION AP L1A AP L1AN...
Page 14: ...1 NOMENCLATURE AND FUNCTIONS 1 3 2 The details of label will be differed by the market...
Page 82: ...11 SETTING ATMOSPHERIC CORRECTION 11 4 Temprerature C Temprerature F...
Page 83: ...11 SETTING ATMOSPHERIC CORRECTION 11 5 Temprerature F...