I??ve adjusted the bubble on my tribrachs many times with no problems. This time however something went odd. I use the little level ring and when I went into the field, the gun was showing level out by more than 2 min. This happened with all the tribrachs. I thought maybe the ring was out, so I adjusted the bubble again using the gun. Now, every time I put the gun on the legs, it is out a lot again. Even with adjusting the bubble. Anybody have any ideas?
I check the many tribrachs I have by placing them on top of each other with the rotating hockey pucks and leveling all of them and rotating them in a circle to see if they maintain level in the level bubbles.
When they can do that, you have a good adjustment.
Either something is loose or the gun has a bad sensor.
If the gun says it is level as you rotate it and the tribrach bubble agrees, then you should be able to put the gun on the tribrach in a different rotation and still be close.
Carefully inspect all of the contact points on both the gun and the tribrac.