Alignment Methods
After the laser is set up at the correct elevation and the
correct grade is entered, the last step is to align the beam
to the forward manhole using one of these methods:
1) Manhole Mount with Transit
2) Special Transit and Rod Group
3) Stringline
4) Plumb Bob
Manhole Transit Method
This method can be used with the Special Transit or any
standard transit (ideally one that has a back sight – flop
– capability). Use the Manhole Transit Clamp system to
support the transit. The laser is set up in the manhole using
leg sets, or the trivet.
1. Secure the Clamp Body and Mast (Figure C). Position
the clamp (1) over the top edge of the manhole so the
mast (2) is plumb enough to easily level the transit
when mounted. Tighten the clamp screw (3), until the
clamp points are firmly embedded in the sides of the
manhole. The mast can be further adjusted to plumb
using the lever (4) locking the mast pivot.
Secure the Arm - Slide the arm clamp support (5) and
the arm clamp (6) over the mast and secure. Insert the
arm (7) into the clamp. The clamp allows complete
flexibility to raise, extend, and position the arm so the
transit mount (8) is over the manhole center. The transit
mount is a 5/8 x 11 male attachment for mounting a
standard transit. The AGL Special Transit is mounted,
using an adapter assembly.
Aligning the beam with the AGL Special Transit
2. Mount the Special Transit and adapter to the mount at the end of the arm. Adjust the arm so the
transit is roughly over pipe centerline and in line with the laser (Figure D). Adjust the vertical
crosshair exactly to the forward manhole marker using the forward marker knob.
3. Align Transit to Laser - Tilt the transit down and sight the line pivot green LED. On the transit,
use the laser centerline knob to adjust the vertical crosshair until aligned exactly with the green
LED. Repeat steps 2 and 3 until the vertical crosshair is on both the forward manhole marker
and the green LED on the unit.
4. Align the Laser Beam to the Transit - Place a target in the ditch approximately 15’ (5m) in front
of the laser. Looking through the transit at the target, adjust the beam left or right using the
alignment buttons on the remote control until exactly centered on the vertical crosshair. You
should then be able to swing the transit from the beam, to the green LED, and to the forward
manhole marker, with each being aligned to the crosshair (Figure E). Repeat steps 2, 3 and 4 if
necessary. When all three are accurately aligned, pipe laying can proceed.
1
2
3
4
5
6
8
7
5
Figure C
Figure D
11
3
4
2
Figure E
