Product Description

Nedo precision Invar levelling staffs are used for first-order levelling and for challenging work on large scale construction sites, for example tunnels, roads, dams or power plants. The graduation of the precision Invar levelling staffs is engraved in the paint coating with an interferometrically controlled laser beam, ensuring superior graduation accuracy and edge sharpness. The permissible deviation is |ΔL| ≤ 0.01 + l ∙ 10-5. Nedo Invar levelling staffs thus conform to the highest accuracy class A as per DIN ISO 12858-1. 

The European research centre CERN operates the world’s largest particle accelerator. Here elementary particles are accelerated to nearly the speed of light and then made to collide. Scientists use these experiments to explore conditions at the time of the Big Bang, when matter came into being. The experiments are performed in a 27 km ring of superconducting magnets. These magnets as well as countless of sensors must be kept in perfect alignment.

Exact horizontal positioning of these components over a distance of 27 km was a huge technical challenge. It was solved with Nedo precision Invar levelling staffs. The photo shows the inside of the tunnel. A Nedo precision Invar levelling staff has been placed at a reference point on the pipe.

Features

• Body of Invar staff made of rigid aluminium profile with anodised surface
• Yellow lacquered graduation side; print protected by a 0.1 mm polyester coating
• Invar tape seated in protected groove of staff profile and tensioned by soft spring to compensate the extension coefficient of the staff profile. Coefficient of thermal expansion < 1,5 ppm/k
• Foot plate slightly protrudes from staff body
• The foot plate is made of stainless chrome steel and is hardened and ground
• Equipped with circular bubble and fold-away handles as a standard. The handles are zinced and powder-coated.