My recent stumble related to forgetting to turn on the compensators in my total station, has led to (what else?)...more questions.
I'm having a very hard time finding an exact definition of what the three "compensation errors" are in "Topcon-Speak". They sure don't discuss it in the manual, or anywhere I can find online. Leica Systems has a much better description of what Compensator index errors are. See here:
They call them "longitudinal" and "transverse" zero point errors (l and t).
Can anyone familiar with Topcon total stations help translate? If VCo is l, and HCo is t, what the heck is HAx?
OK. No bites. Or, no one knows. I understand that once you're in this for a living, you just go through all the checks to make sure the work comes out right without worrying too much about what it all means. I'm not in that boat. So...I took a stab at it myself:
First, the two Collimation errors: HCo and VCo (Topcon), aka t and l are the adjustments that tell the compensators where "zero" on the scales is relative to gravity, so that it will always make sure that the vertical axis (horizontal circle) and trunnion axis (vertical circle) alignment of the telescope "yoke" (relative to gravity) are correct.
Then, HAx must be the correction between the trunnion axis (in plan view) to zero on the horizontal circle. Not sure how that could ever get out of whack, but there's nothing else I can think of that fit's the "Horizontal Axis" moniker.
Finally, above all this, the telescope rotating about the trunnion axis needs to be zero'd. In Topcon Speak that's "V datum = 0"; not sure what it's called in Leica, Nikon, or Trimble etc.
Think I've got this about right?
The collimination should be the amount adjusted in the instrument so that the difference between face 1 and face 2 are compensated in only face 1 readings hax is probably the horizontal axis leveling compensation so when you turn the gun 180 it still reads level these all should be checked and reset after large temp changes and periodically.
I think it's what Trimble calls the trunnion error. The amount by which the horizontal angle varies as the steepness of the sight increases..
squowse, post: 333803, member: 7109 wrote: I think it's what Trimble calls the trunnion error. The amount by which the horizontal angle varies as the steepness of the sight increases..
That would make sense then, because the routine they put you through with Topcon is to site a target more than 10 degrees above horizontal, up to 10 times with both faces.
Is there also a menu option to set the tilt or level compensation and to see level electronicly?
mvanhank222, post: 333832, member: 8673 wrote: Is there also a menu option to set the tilt or level compensation and to see level electronicly?
Yes. When "TILT" is on (the way it should be), it gives you a warning if it's out by more than "x" seconds (I can't remember what it's set at). In that case, when you're leveling it just gives you "Tilt Over" (or something like that).
But I discovered that if you go to the Tilt menu, when you're leveling the instrument, you can use the readouts for extremely sensitive leveling. Of course, that's only worth a hill of beans unless the instrument is completely adjusted (compensators, H axis, V datum, etc.).
There should be a option to set the tilt that is what you diagramed as collimination.
