Topcon Automatic Level AT-B2

Center the bubble in the circular level

Turn the nearest leveling screw to the sighting axis 1/8 of a turn to the right or left

Check the movement of the horizontal cross-line

Tap the tripod legs or the main body while sighting a clear target

Check if the cross-line bounces, then immediately returns to the original position

It is advisable to check the movement of the automatic compensator before use

1. Set the instrument halfway between two points, A and B, 30 to 50m apart. Take readings a₁ and b₁.

2. Set the instrument at a point 2 m from point A. Take readings a₂ and b₂.

Leave the telescope sighted on point B.

If b₂′ = b₂, the horizontal cross-line is normal and no adjustment is necessary.

When b₂′ and b₂ are different, adjust the cross-line as follows:

3. Unscrew and remove the adjusting screw cover.

4. Use the adjusting pin to eliminate the difference between b₂′ and b₂.

1. Adjust the leveling foot screws to center the bubble in the circular level.

2. Turn the instrument 180° (or 200 gon).

If the bubble is inside the circle, no adjustment is necessary. If the bubble shifts from within the circle, adjust as follows:

3. Compensate for one-half of the shift by adjusting the leveling foot screws.

4. Eliminate the remaining half shift with the circular level adjusting screws using the hexagonal wrench.

5. Turn the instrument 180° (or 200 gon). If the bubble remains in the circle, adjustment is complete.;