Double Vial Rover Rod
- Thread starter Jim Campi
- Start date
Donald E Robinson
Active Member
There is a black rod holder (very cheap), that you can get at most survey suppliers, that attaches to the plate on your tripod. You attach the rod to the device and plumb center the frog-eye bubble. Rotate the rod 180° and check it. If the bubble is out, adjust it only ½ way to the correct position. Repeat the procedure until the bubble remains centered at all rotation points.
Note: When you adjust the bubble, adjust it only ½ way. If you adjust it to the center you have just mirrored your error when you rotate it 180°, again.
Note: When you adjust the bubble, adjust it only ½ way. If you adjust it to the center you have just mirrored your error when you rotate it 180°, again.
Joe Paulin
Well-Known Member
There are many ways to adjust a survey rod level. After using many different techniques over the years, I now mount a Seco rod tripod to the rod (http://www.surveying.com/Products/Bipods-and-Tripods/Thumb-Release-Bipods-and-Tripods/5218-02-FLY) which is standard equipment in my truck now anyway and do exactly what Donald does. You can do this very quickly anywhere - in the field or at the office. It's so quick I have got in the habit of checking it daily.
I have a cabinet mounted to the wall. I dropped a plumb bob from the corner of it to the floor and marked a spot (don't tell my wife). I then put the pole on the mark and extend it to have a light compression to my spot on the cabinet. I then adjust away. After I feel like I have it adjusted, I turn it 180° to make sure the bubble is still centered. You probably have places like this in your home or office. Of course, you can also go to the hardware store and buy a couple of brackets, mount them to a wall and do the same thing.
Jim Campi
Active Member
I appreciate all the comments. Will try several of these and see which works best.
Joe, since you are checking on a routine basis, how often are you finding that the level requires adjustment from nothing more that routine, daily use?
If memory serves, Kelly set something up as well. I believe he posted it shortly after the LS was initially released. Anyone recall that post?
Joe, since you are checking on a routine basis, how often are you finding that the level requires adjustment from nothing more that routine, daily use?
If memory serves, Kelly set something up as well. I believe he posted it shortly after the LS was initially released. Anyone recall that post?
Joe Paulin
Well-Known Member
It all depends how rough I am on it the day before...
. It should be noted that I don't use the new double vial LS rod, I use Seco rods. Seriously, it's not hard for a bubble to get out of adjustment, and don't assume that it is adjusted properly on a brand new rod. I find that mine is in good adjustment most days. Jolts, sudden impacts & bumps are likely to jar it out of adjustment a little. Realistically, I probably adjust it about once a week.
. It should be noted that I don't use the new double vial LS rod, I use Seco rods. Seriously, it's not hard for a bubble to get out of adjustment, and don't assume that it is adjusted properly on a brand new rod. I find that mine is in good adjustment most days. Jolts, sudden impacts & bumps are likely to jar it out of adjustment a little. Realistically, I probably adjust it about once a week.Joe Paulin
Well-Known Member
That would get it close, but any of the above methods would be better IMO. I guess it depends how plumb you need it. You could do this after (calibrating the LS) and then rotate the rod 180 to see if it was good or not. I would not recommend relying on this for control or boundary use.
Joe Paulin
Well-Known Member
Remember, you can use the method Donald described about anywhere. The bottom point needs to be stationary, the rod needs to be able to rotate about it's axis without moving. Level rod and rotate 180 degrees. Lots of guys use their tailgates - stick the point in the ground a bit while using part of the tailgate as a rest for the rod to rotate around without moving.
Joe Paulin
Well-Known Member
Lots of info on another site we've talked about in another post...
http://surveyorconnect.com/community/threads/how-do-you-check-your-prism-pole.306319/#post-306346
I find it funny Mr. McMillan actually agrees with me in this post!
http://surveyorconnect.com/community/threads/how-do-you-check-your-prism-pole.306319/#post-306346
I find it funny Mr. McMillan actually agrees with me in this post!
No, the opposite of this true. The level vials must be used to calibrate the internal tilt sensors!
I would add that is is best to brace the pole towards top of it as much as possible. If the pole is not perfectly straight and there is some curvature in it, the only way to correct for this is to brace it near the top.
Wes Cole
Active Member
I've had this happen on other rods before. I backed all three screws out until the vial was loose, then began working clockwise slightly tightening the screws until they were snug enough to keep the vial from moving and I didn't think they'd work loose. Then proceed with normal adjustment making sure all crews were still snug when adjusted. This may not be the best way to reset the adjustment screws but it worked...
Donald E Robinson
Active Member
Jim,
When I make any adjustments I find that tightening the screw(s) first, closest to the bubble, but just a little. You want to put a little stress on the vial. Then loosen the other screw(s), just a little, to release the stress All the screws should be tight when you finish. Just take your time.
When I make any adjustments I find that tightening the screw(s) first, closest to the bubble, but just a little. You want to put a little stress on the vial. Then loosen the other screw(s), just a little, to release the stress All the screws should be tight when you finish. Just take your time.
Jim Campi
Active Member
I used the Javad rod with a seco bipod. The circular level is centered in the housing with a pin in the bottom center of the vial. When the vial is properly calibrated the annular space (area between the vial and housing) will be equal.
Tightening an adjustment screw brings the bottom of the vial closer to the housing (causing the bubble to move away from the screw).
Of course all the screws must be tight. So, tightening one screws requires loosening another.
This was a maddening process the first time around. I made a few adjustments and can now calibrate quickly and easily.
This is a simple a fast process now. I appreciate all of the input.
Tightening an adjustment screw brings the bottom of the vial closer to the housing (causing the bubble to move away from the screw).
Of course all the screws must be tight. So, tightening one screws requires loosening another.
This was a maddening process the first time around. I made a few adjustments and can now calibrate quickly and easily.
This is a simple a fast process now. I appreciate all of the input.