High Precision Optical Collimator

Applications

The high precision optical collimator allows detection of movement of one or more points of the dam with respect to two distant points presumed fixed, generally placed on the dam shoulders.
This instrument is mainly used for monitoring concrete and earthfill dams. It can also be used for monitoring:

• bridges
• bulkheads
• tunnels
• embankments
• viaducts
• mines
• Other

Features and Benefits

• High resolution optical system
• High precision measurements
• Sturdiness and stability
• Easy to use
• Rapid precision measurements

Measuring Principle

The instrument is very simple; the collimator allows the measurement of the relative displacement of several points along an optical alignment fixed and invariable over time; the alignment is defined by the collimator and a fixed reference target.
The collimator is installed at a point known as the “station point”, generally in one of the shoulders of the dam crest, and such that it is not affected by possible movement of the dam body.
The points to be monitored on the dam body are formed by fixed bases for the mobile target which is positioned there during the monitoring phase; The fixed reference target, compared to the points to be monitored, is located opposite the collimator on the other shoulder of the dam.
Measurement consists of measuring variations in position of points being monitored with regard to the alignment.
The amount of movement will be equal to the movement required for the mobile target to return to its original alignment.
When the point, where movement is to be monitored, is not at the same height as the station point and the fixed target, that is the reference line, the mobile target can be observed by turning the telescope on its own horizontal axis. The collimation axis defines a vertical plane, allowing interception of the mobile target and measurement of its displacement in respect of that plane. The collimator is supported by three spherical feet, two with leveling screws, on a fixed base cemented in place, located externally to the structure on a special pillar.
The micrometric movements of the collimator have been designed to facilitate pointing also at great distances.
The high quality of the optical system and the sturdiness of the instrument ensure high precision measurements . The objective lens has a resolution of 1.5 “.
The pointing system, according to which the operator centers the micrometer wire between the references of the reference targets, increases the resolution to 0.32 “.

Technical Specifications

Accessories and spare parts

support base for collimator – base for the univocal positioning of the collimator
support base for removable fixed targets – base for the univocal positioning of fixed targets
base for removable targets – base for the univocal positioning of movable targets (measuring points) – same base as the fixed target
fixed removable targets – for alignment with the collimator, removable, to be placed on relevant bases
Fixed target for walls – as an alternative to fixed removable targets, to create the optical alignment axis with the collimator; to fix to the wall
Mobile target with one or two movements – for measuring deviation from the optical reference axis or plane

SPECIAL ACCESSORIES

Adapter between collimator base and target
For installation of removable fixed targets on the collimator base; recommended for long collimation distances, when alignment from both fixed locations is required.
Rotating adapter between collimator base and targets
For 180° rotation of the target screen; to be used when monitoring of both fixed locations is intended
Rotating adapter between target base and targets
For use on bases for targets when the same target is subject to observation by two misaligned alignments
Sliding adapter between target base and target; H = 700mm
To raise the target with respect to the support base, height adjustable from 50cm to 70cm with steps of 5cm (other heights and steps on request)
Fixed adapter between target base and target H = 50cm or 100cm
To raise the target with respect to the support base (other heights and steps on request)
Sliding adapter between the head element of the USBR settlement gauge column and collimation targets
For installing of a collimation target on the USBR settlement gauge column. Adjustable height in steps of 5cm, total max height 700mm, (other heights and steps on request)
Fixed adapter between the head element of USBR settlement column and collimation targets.
For the junction connection between the USBR settlement gauge column and the collimation target, max height 700mm (other heights on request).
Adapter between collimator base and total station , leveling benchmark, prism and signal rod
For the use of devices for topographic measurement on the collimator base
Adapter between target base and total station, leveling benchmark, prism and signal rod. For the use of devices for topographic measurement on the target base
Fixed base for theodolite complete with fixing screw and lid.
For the use of total station in a fixed position, removable
Also available are:
Fixed and mobileleveling benchmark
Removable signal rod
Prisms

Measure principle