Tribrach Level Bubble Calibration

Agree this is a great method but have found some of my older tribrachs clamp my newer Geomax (Lecia) instrument such that it does not rotate on a horizontal plane, either the angle of the slots in the pins from instrument that get clamped or the support pins in top of tribrach don't quite work together. Thankfully the Sokkia tribrach uses a rotating plumet (AP41) so can rotate 180° to check/adjust bubble.

And you are still using said tribraches? 

Clearly not with the robot but the Sokkia tribrach and the Sokkia AP41 plummet make an excellent backsight/GNSS base tool as you can check calibration instantly in field just by spinning 180°. You do however have to use a different method to adjust them than outlined in video which was the point I was trying to make as something to watch out for given intended audience appears to be newbies.

The robot only gets used with a GDF321 dedicated to that instrument only. Using old tribrachs with robots a bad idea as most can't handle the hysteresis. One of the firms I contract to kept using old topcon tribrachs when they got their first Lecia TS15 to keep force centering traversing, that practice got knocked on the head real fast as the topcons just couldn't hold the bearing.