The accurange 3000 distomat was borrowed to evaluate
it as a replacement for our current distomats. It was installed next to
distomat 1 and run for testing. We have the 2 millradian version.
28apr11: distance measurements vs sample
average. (top)
On 28apr11 distance measurements were made with the
accurange 3000 distomat. It was setup to measure the distance from the
rim road (distomat 1 location) to the retroreflector at corner 12 of
the platform. These measurements were similar to the 20apr11
measurements. The setup for 28apr11 was:
Page 1: accurange 3000 distance vs time for 4 sample averages.
The rms is included in each title
Page 2: rms vs sample average and old distomat measurements:
top: accurange 3000 rms (in mm) vs counts.
The black line shows the 4 measurements
The red line is the expected rms vs counts assuming rms for
200 counts is
correct
The rms decreases with counts, but not as rapidly as
expected. This is probably caused by slow variations in the measured
distance by the accurange3000.
Bottom: Measured distance with old distomats.
black,red green are the distances measured by the old
distomats. The median value has been removed. corner 12 (black) is the
same distance measure the accurange3000
These measurements were made once every 2 minutes (spending
about 6 seconds for each measurement).
The maxium variation over 1 hour was 8 mm. For each 2 minute
measurement if varied by about 2 mm. This is much more than the
18
to 37 mm rms of the accurange 3000.
Page 3: return power measured by accurange 3000
each frame is a different sample average.
Page 4: plot disance measurement vs returned power.
The returned power is strongly correlated with the distance
measured.
You would expect the returned power to decrease with
increaesed distance unless there was some pointing issue.
Page 5: accurange 3000 temperate during measurements.
the temperature measured for each measurent is plotted. there
is no obvious dependencies.
Summary:
the measued rms for various sample averages is larger than
expected (1 mm).
The measured distance is positively correlated with the
distance measured. There is probably some kind of alignement
problem betweeen the distomat and the retroreflector.