Collimation Systems

High Precision Optical Collimator

///High Precision Optical Collimator

Description

The optical alignment collimator is an instrument produced by Pizzi Instruments and designed especially for monitoring movement at dam crests.
The instrument, of notable optical-mechanical characteristics, with an objective lens of 80mm diameter and 60X magnification, allows optical alignment between two points considered fixed, this alignment defines a fixed vertical plane which allows the detection of movement of points in the structure aligned with it.
The collimator is always positioned at the same station point thanks to special bases which allow repeat placing in the exact same position.
On the opposite side to the points being monitored, a target is positioned on a special base, fitted with three special supports to allow precise positioning.
Measurement is performed using a special target, known as “mobile target”, positioned on the points of the structure to be monitored, using the special support bases which allow its univocal positioning. With this system, accuracy of 0.2 mm over a distance up to 300m can be achieved.

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

Diameter of the lens 80 mm
Magnification 60x
Zenithal Rotation ± 35°
Azimuthal Rotation 360°
Weight of the instrument 21 Kg
Housing Watertight trolley in polypropylene
Dimension of the housing 600x410xh310
Weight of the housing with the instrument 32 Kg

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

Technical Assistance

If you have any requests or questions about our instruments or if you have special needs that require different solutions from the standard, please contact us. Our team will provide all the necessary information and will be very happy to work with you to study, develop and customize instruments and solutions suitable for your specific needs.

All information in our datasheet is subject to change without prior notice.
Please check the datasheet/details carefully and contact Pizzi Instruments for further information.

Measure principle

The instrument is very simple; the collimator allows for the relative measurement of the displacement of several points arranged along an alignment fixed and invariable in time; the alignment is defined by the collimator and a fixed reference target.
The collimator is installed in a point called “station point”, generally in the shoulder of the dam’s crest, however, that will not be affected by possible dam body movements.

The points to be examined on the dam body are materialized from fixed bases, on which the target to be measured is then applied; the fixed reference target is, compared to the points to be controlled, on the opposite side of the collimator on the other shoulder dam.
The measurement consists of measuring the variations of the position of the points to be controlled in respect of the  alignment.
The entity of movement will be equal to the movement necessary for the target to get back on the alignment of departure.
When the point where we wish to put in evidence the displacements is not located at the same height of the station point and the fixing point targets, namely the alignment of reference, it will pass to the observation of the mobile target by rotating the telescope around its own horizontal axis. The collimation’s axis will describe a vertical plane allowing to intercept the target and then the displacements of the structure in respect to that plane.
The instrument is  supported with three spherical feet, two of which with leveling screws on a fixed walled base, located externally of the structure on a appropriate pillar.
The micrometric movements of the collimator are studied in such a way as to facilitate the pointing also at great distances.
The high qualities of the optical system and the sturdiness of the instrument, ensure a very precise pointing. The objective has a resolution of 1.5 “.
The pointing system, according to which the operator centers the wire of the micrometer between the references of the targets, increases the resolution power bringing it to 0.32 “.

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