Home > Technology > AMTS Monitoring Systems > AMTS L-Bar Prisms

AMTS L-Bar Prisms

L-Bar Prisms are versatile survey prisms used with AMTS to monitor displacements and deformations of structures. The L-Bar bracket provides easy installation on almost any location: tunnel walls, building facades, soldier piles, retaining walls, bridge decks, and more. Datasheet

L-Bar Mini Prism

Lbar Mini Prism

The L-Bar Mini Prism is installed on tunnel walls, building facades, foundation slabs, retaining walls, and almost any other location. It is used for both monitoring points and control points.

Prism: 25 mm optical glass with silver backing and clear appearance.

Offset: -25.5 mm for Topcon, Trimble,etc. +8.92 mm for Leica.

L-Bar Bracket: Black anodized aluminum, 3 inch arms, two 5/16 inch holes for mounting screws.

L-Bar Micro Prism


The L-Bar Micro Prism is a tiny 0.5 inch prism designed for low visual impact and is nearly invisible in most environments. This prism is best used for indoor monitoring points.

Prism: 12.7 mm optical glass prism with silver anti-reflection coating.

Offset: -17.5 mm for Topcon, Trimble, etc.

Bracket: Black-anodized aluminum bracket has 25 mm arms and a single mounting hole.

L-Bar 360 Prism

L-Bar 360 Prism

The L-Bar 360° Prism can be targeted by two more AMTS as a monitoring point, control point, or a tie-in point between separate AMTS networks.

Prism: Omni-directional prism consists of 6 triple prisms.

Offset: -6.5 for Topcon and Trimble, 27.9 for Leica.

Bracket: Black-anodized aluminum bracket has 3-inch arms and two 5/16-inch holes for mounting screws.

L-Bar Prism on Magnetic Base

L-Bar Prisms on Soldier Piles

L-Bar Prisms on Facade

L-Bar Prisms on Facade

L-bar prisms in tunnel

L-Bar Prisms in Tunnel

Advantages L-Bar Prisms

Easy Installation: The compact L-Bar bracket can be installed in any orientation and fits nearly any location.
Durable: The L-Bar prism is waterproof and dustproof, suitable for any environment.
Low Visual Impact: L-Bar prisms are compact and almost unnoticeable from street level.
Cost Effective: L-Bar prisms are relatively inexpensive and provide a low cost per monitored point.


  1. Choose locations that provide a clear line of sight between the L-Bar prism and the AMTS.
  2. Determine the best orientation for the L-Bar bracket, install the anchors, and mount the bracket. Magnetic bases are also available and eliminate any drilling.
  3. Attach the prism to the bracket, rotate it to face the AMTS, and tighten the mounting screw.

Request a Quote for L-Bar Prisms