Features

Our digital laser pantograph ALPHA measures vectors in three dimensional space and then converts them into 3D vector drawings on a linked portable computer in real time.

This piece of equipment was designed specifically for use in archaeology and the buildings & historic monuments sector. It is particularly well suited to recording interior spaces three dimensionally, and stratigraphic, stone-for-stone recordings e.g. on urban sites or for complicated archaeological finds.

A range of up to 7m diameter can be recorded from one position; plana, layers, sections (floors, walls, ceilings) can all be surveyed without moving the instrument. One of the advantages of this pantograph is its spatial manoeuvrability and its ability to record around obstacles, i.e. complex undercuts or hollows, and objects that are difficult to reach. The measuring accuracy is approx. 1cm but this depends on the ground colour and range.

The instrument works in the same way as the total station. This means that the pantograph measures distances and angles in three dimensional space after free stationing has been carried out. This surveying method has only become possible within the last few years thanks to developments and improvement in the accuracy of surveying lasers.

The accuracy of the laser beam depends on ground colour; dark colours do not reflect the light as well as a light colours. The laser measurements are very precise up to a distance of 2m (+/- 0.75 cm). Inaccuracies of between approx. 2-5cm only appear when the laser beam range is extended to approx. 5-10m. More efficient and more powerful lasers could theoretically be built into the pantograph, but the higher rate of accuracy would also be reflected by a higher price.

The instrument allows direct, controlled measurement of points and allows undercuts and hollowed out areas to be recorded. At present only a limited number of these instruments have been produced.

All of the movements within the various spatial axes are offset by rotary encoders. The entire pool of measurement values is then converted into 3D coordinates by seven microcomputers connected to a central computer (master/slave network). The ingoing 3D coordinates are then transferred into a portable computer (Pocket PC) for further processing. This portable computer is plugged into the cantilever arm. The small size of the portable computer is of great advantage for transportation and it's position at eye-level on the cantilever arm means that it is easy to access and operate.

Construction & Technical Details