Tips On Surveying.That Infuriating Bubble & Closing The Survey

[sophiadaniel]

I am a trainee civil engineer and learning how to carry out succesful surveys. It seems i am unfortunately inept at getting turning the dials to 'get the bubble' in the correct place.

Any tips?

Also struggling to understand 'Backsight' and 'Changepoint'

Thanks

 

[Apakrat]

Are your survey instruments using single "eye" or Dual "tube" bubbles?

1. With "eye" bubbles, select one adjustment screw, cause the bubble to move so that it and the etched center circle points directly toward any another adjustment screw then adjust that screw to pull or push the bubble into the center of the "eye" bubble. Many times you will only have to move the bubble directly into center point.

2. Double "tube" bubbles is a little more complicated but easy if you just remember that opposing adjustment screws meed to be turned in almost identical amounts but in opposing directions. To accomplish opposing directions, remember to move your thumbs in different directions and that THE BUBBLE WILL MOVE IN THE DIRECTION THE LEFT THUMB MOVES.

"Backsight" is the direction or point you are measuring from. "ChangePoint" in my survey days 30 years ago, meant to pick up the instrument and move to another set-up point. But, new-age language may mean the point of which you are measuring an angle to from at the "Backsight" point.

At 74th year working on IR-One2 PhD from UHK - - -

 

[Apakrat]

PS --- Still a damn shame schools of higher learning ignore surveying as being a peons profession, sub servant to ALL engineering disciplines!!!

At 74th year working on IR-One2 PhD from UHK - - -