Nedo Precision Invar Levelling Staffs
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.
Nedo Precision Invar Levelling Staffs
| Staff shoes | Ref.-No. Graduation 15a | Ref.-No. Graduation 19a | Length | Weight |
| Standard staff shoes | 391 189 | 1 m | 3.0 kg | |
| Standard staff shoes | 392 185 | 392 189 | 2 m | 4.3 kg |
| Standard staff shoes | 393 189 | 3 m | 5.5 kg |
Calibration Certificates
As an option, each Invar staff can be supplied with a calibration certificate.
Certificates are issued by the Technical University of Munich or by Nedo, depending on the customer’s requirements..
Ref.-No. 399 511 Length calibration without temperature cycle, adjuster Nedo Dornstetten
Ref.-No. 399 519 Length calibration without temperature cycle, adjuster Technical University of Munich
Ref.-No. 399 521 Length calibration with temperature cycle, adjuster Technical University of Munich
Precision Invar Levelling Staff Accessories
Nedo LED Invar Staff Illumination
LED Invar staff illumination for Nedo high precision Invar staffs. The Invar staff illumination allows measurements to be taken with the Invar staff and a digital level in absolute darkness.
It can be used for example in mines, tunnels, night-time construction sites and for building monitoring. The measurement results are just as precise as measurements in daylight. Thanks to its compact design and integrated power supply, the mobility of the Invar staff is not reduced. Highly efficient LEDs in combination with specially designed optics and an optimized electronic unit ensure a long operating life. The lighting does not weaken during the battery running time, so dependable measurement is always possible. The system can be fitted to an Invar staff by the customer himself using standard tools, and requires no maintenance. The circular level of the Invar staff is additionally lit to permit precise measurements.
Features:
- Protection class IP 54
- Operating temperature -10°C to +50°C
- Level lighting
- Battery status display
- Detachable rechargeable battery with low self-discharge
- Battery life 5 to 10 hours depending on length
- Supplied with rechargeable batterie and charger
Ordering data
Ref.-No. 396117 suitable for all 3 m bar code Invar staff
Ref.-No. 396118 suitable for all 2 m bar code Invar staff
Nedo Telescopic Struts
Telescopic struts are available as accessories for 2 m and 3 m precision Invar levelling staffs. The easy to handle telescopic struts ensure a secure stand of the precision Invar levelling staffs.
Ordering data
Ref.-No. 399211 suitable for 2 m precision Invar staffs
Ref.-No. 399311 suitable for 3 m precision Invar staffs
Nedo Transport Case for 2 Invar Staffs
Case for safe transport and storage of Nedo precision Invar levelling staffs. The transport case is made up of a sturdy aluminium frame and strong plastic honeycomb structured wall panels. The corners feature robust protectors. Handles allow for an easy handling. In addition, the case has a foam lining to protect the precision Invar levelling staffs. The transport case can accommodate two precision Invar levelling staffs, one precision Invar levelling staff with telescopic struts or one precision Invar levelling staff with illumination.
Nedo Transport Case for 2 Invar Staffs with standard staff shoes
Ref.-No. 395111 for 1 m staff length
Ref.-No. 395121 for 2 m staff length
Ref.-No. 395131 for 3 m staff length
Nedo Transport Case for 2 Invar Staffs with wide staff shoes
Ref.-No. 395221 for 2 m staff length
Ref.-No. 395231 for 3 m staff length