Profile
WG 5.42 is concerned with the traceable realization of distances from around 30 cm to one kilometer. It conducts research and development in the field of absolute interferometry with refractive index compensation, maintains the national standard (the so-called geodetic basis) in this field, provides calibrations of laser-interferometer systems, of electronic distance-measuring devices and of precision tape measures, and participates in corresponding standardization committees at DIN, ISO and SCGD.
Research/Development
The primary focus of our work in research and development is on the development of new interferential measurement methods (and on the further development of existing methods) for the traceable measurement of large distances with low uncertainties, especially under realistic external conditions. Our goal is to implement these measurement methods in our Working Group’s range of services, and to apply these methods to precision engineering and geodesy.
Projects
Current projects
- EMRP, Research Projects:
- JRP SIB60 "
Metrology for long distance surveying"
Head of Project:
F. Pollinger
Processing:K. Meiners-Hagen, J. Mildner; 07/2013- 06/2016- Development of a solid-state laser-based air-index compensated absolute distance interferometer as novel primary standard for
geodetic baseline calibration (WP1 and WP4) - Development of a frequency-comb based heterodyne multi-wavelength interferometer (WP3)
- Development of a solid-state laser-based air-index compensated absolute distance interferometer as novel primary standard for
- JRP IND53 "Large volume metrology in industry"
Head of Project:K. Meiners-Hagen
Processing:G. Prellinger, F. Pollinger; 06/2013- 05/2016- Development and verification of a refractive index compensating self-tracking device (WP2, WP3, and WP5)
- Development and verification of a refractive index compensating self-tracking device (WP2, WP3, and WP5)
- JRP SIB60 "
Completed projects since 2005
Services
WG 5.42’s field of work is the calibration of one-dimensional length-measuring instruments whose measuring ranges extend from a few centimeters to several hundred meters. To this end, we have two highly specialized standards at our disposal: the geodetic basis and the 600 m baseline. Below, you will find standard services in the field of length-measuring instruments and laser interferometers for which a calibration certificate can be issued with a CMC seal; these services are accredited in accordance with CIPM-MRA. For special challenges, however, customized solutions can also be jointly worked out in discussions. If required, we can also provide special calibrations for measuring probes (e.g. calibrations for specific geometries).
Calibration of Laser InterferometersCalibration of Laser Interferometers
Measurand | Range | Expanded Uncertainty |
| Laser-interferometer system: error of indicated displacement with refractive index compensation L | to 2 m | Q[0,015; 0,031 L] in µm, L in m |
| Laser-interferometer system: error of indicated displacement with refractive index and thermal expansion compensation L | to 2 m | Q[0,015; 0,074 L] in µm, L in m |
Calibration of length measuring systemsCalibration of length measuring systems
| Measurand | Range | Expanded Uncertainty |
| line scale, steel | to 4 m | Q[5,8; 1,8 L] in µm, L in m |
| line scale, invar or glas | to 4 m | Q[5,8; 0,4 L] in µm, L in m |
| tape, overlay, steel | to 50 m | Q[13,4; 2,6 L] in µm, L in m |
| tape, overlay, steel | 50 to 100 m | Q[132; 2,6 (L-50 m)] in µm, L in m |
| tape, overlay, invar | to 50 m | Q[13,4; 0,72 L] in µm, L in m |
| tape, overlay, invar | 50 to 100 m | Q[41; 0,72 (L-50 m)] in µm, L in m |
| tape, sagging, steel or invar | to 50 m | Q[40; 3 L] in µm, L in m |
| Laser range finder (EDM), flat reflector | to 50 m | 460 µm |
| aser range finder (EDM), retroreflector | to 50 m | 102 µm |
Calibrations for probe
On request are calibrations available in special geometry for probe developed and offered.