Q: When I use my prism/antenna poles, I’ve noticed that some are easier to hold still than others. My dealer told me this is because the “bubble sensitivity” of one is higher than the other, with the more-difficult-to-hold pole having higher sensitivity.
This month we are highlighting a technique that a reader has been using for quite a while. Arthur J. Saarloos of Delta Junction, Alaska, sent it in hoping we would share it with the readership.
When I used optical theodolites, I checked and adjusted the horizontal and vertical collimation myself. I noticed in my new total station’s instruction manual that I only have 30 arc seconds or so of adjustment I can use. The manufacturer requires that I return it to an authorized service center for larger collimation adjustments. Why?
I know that the bubbles on my prism/antenna poles can go out of adjustment. How much of a problem is this? And how do I check them to see if they’re in adjustment?
I have a two-part question. I have a total station setting for curvature and refraction correction. To turn it on, I have to select from one of two constants to be used in the correction. Which one should I be using? The second part of my question comes from noticing that my surveying textbook (Moffit & Bossler) uses only one constant for the curvature and refraction correction. Why the difference?
When the target centering feature of my servo-driven total station is switched on and I do a visual check through the telescope, I often find that the telescope cross hairs are not on the target. There seems to be a constant offset above and to the left of the target. My instrument dealer has told me not to worry about this. He says that the instrument has been calibrated and that a software correction is applied. Is this true? Should I be concerned?
