I'm sitting here drinking my morning coffee and I'm wondering if anyone knows what the hysteresis of the good 'ol Wild GDF22 is? Are they suitable for use with a motorized instrument?
thanks 🙂
That is all I use and never have noticed a problem with my Leica 1203 Robot.
Ed
Thanks Ed.
It would be interesting to see the spec sheets for the Wild GDF22 and 21 tribrachs to compare to current Leica offerings. Just some lazy Sunday musings...
Old thread I realise but I have the same question and wondering if by any chance someone who reads it this time may have a definitive answer from Leica?
Visually, it appears the same as the gdf321 under my robot.
?ÿ
what's hysteresis?
Relates to ability of tribrach to resist the stop/start torque that robotic instruments generate so as to avoid orientation drift throughout duration of a setup.
?ÿ
Manual total station not as hard on the tribrach as human user (usually) is carefully/gently turning angles to maintain precision
Hysteresis is getting a different result when approaching a measurement from opposite directions.
In this case it is mostly due to a small mechanical slop or lack of stiffness in the support. For a robotic TS that starts and stops quickly the tribrach and tripod get a lot more twisting stress than when manually operated.
Back in the days of the brass transit the instructions always said to approach the sight by turning the knob in the same direction. In that case it was to eliminate the hysteresis from any slop in the instrument screws and plate clamping mechanism.