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Question about LS15 and stored collimation value

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MenAtWork
(@menatwork)
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I can't seem to find this answer in the manual, and no one can tell me for sure.....when I perform a collimation check and store the value, then perform another collimation check the next day does the instrument used the stored value when taking the C-shot measurements? Do I need to zero out the current collimation value before performing another C-shot?

We used to see values under 10" and now are seeing around 20" and I was curious if it should be zeroed each time.

 
Posted : August 13, 2022 11:39 am
Lurker
(@lurker)
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I don't know how the software was written but it would be a monumental mistake if they used stored collimation values when determining collimation values. When you go into the routine, there should not be any corrections applied to the angles you observe. I'm not sure how to determine that except for grossly mis-turning the angles so that you have an exaggerated collimation value. Then re-running the collimation routine. If the software is not using the stored values you will get reasonable results. If it is using the stored values you will get exaggerated results.

 
Posted : August 16, 2022 7:26 am
MenAtWork
(@menatwork)
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@lurker I figured as much, but it's strange that we cannot get any collimation checks below about 18" on a basically brand new instrument. We have an old DNA03 that gives us around 3" or less. 

 

We are using this for leveling 

 
Posted : August 25, 2022 3:36 pm

Lurker
(@lurker)
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@menatwork Your instrument may not be the problem at all. Perhaps something about the tribrach has changed that allows a slight movement. Perhaps the tripod is not as rigid as it once was. A loose head, a loose foot, or a loose portion of a leg can easily add seconds to minutes to your angles because of the torsion exerted upon them.

I agree 18" is high compared to all of the values I've seen, but if it works properly and produces correct results, I wouldn't sweat it so much. I suspect the issue lies outside of the instrument itself.

 
Posted : August 26, 2022 10:32 am