Post by administrator on Nov 5, 2004 16:21:27 GMT -5
Levelling Tip
A levelling tip:
When doing a long level run with an automatic level and you've got many change points along the way, it's easy to build up considerable error along the way.
One way of combating this problem is by double runs.
It starts out like any level run, a backsight to your benchmark/station/TBM etc. At the next stage you'll be taking a foresight on a station/manhole/change point or whatever, record the reading, the within about a metre or so of the foresight you've just taken, take another one. Record this foresight on another page in your field book.
When you move your set-up you then backsight both points, in turn.
From here you can work out your Height of Collimation from both backsights. If the don't match then you've got an error in one of your readings, which you can check right there.
This can save time and headaches, so you won't have to re-run that long level loop.
Hope this is of some use to you,
Best regards,
Paul Foley.
A levelling tip:
When doing a long level run with an automatic level and you've got many change points along the way, it's easy to build up considerable error along the way.
One way of combating this problem is by double runs.
It starts out like any level run, a backsight to your benchmark/station/TBM etc. At the next stage you'll be taking a foresight on a station/manhole/change point or whatever, record the reading, the within about a metre or so of the foresight you've just taken, take another one. Record this foresight on another page in your field book.
When you move your set-up you then backsight both points, in turn.
From here you can work out your Height of Collimation from both backsights. If the don't match then you've got an error in one of your readings, which you can check right there.
This can save time and headaches, so you won't have to re-run that long level loop.
Hope this is of some use to you,
Best regards,
Paul Foley.
