linebender, post: 347163, member: 449 wrote: Why measure up? HI is irrelevant when you BS the BM and FS using the same rod.
When running a conventional traverse, I use stationary targets on tripods whenever it's practical. I need good measure-ups for the points to have correct elevation.
If the lines are on the long end of the spectrum, I'd expect that the variation in the refraction coefficient on different lines in different conditions will tend to flood any error due to small HI errors.
I looked at the tape again today as I was measuring the slant height of the instrument and thought that a standard error of +/-0.005 ft. was if anything a bit on the sloppy side.
I have found, and use, 3mm on nearly all the different types if jiggers I have used. That's 0.01' in funny numbers...
