| Zugriffsnummer | 20752 |
| Dokumenttyp | Konferenzartikel |
| Sprache | Englisch |
| Titel | Air refractive index compensation in length measurements by optical interferometry |
| Autor(in); Institution |
Meiners-Hagen, Karl; 5.4, Interferometrie an Maßverkörperungen, PTB-Braunschweig
Abou-Zeid, Ahmed; 5.4, Interferometrie an Maßverkörperungen, PTB-Braunschweig
|
| Quelle/Jahr | Proceedings of ISMTII 2007 : the 8th International Symposium on Measurement Technology and Intelligent Instruments:(2007), 51 - 54 |
| Herausgeber(in) |
JSPE Technical Committee for Intelligent Nano-Measure
|
| Verlag | Sendai: Tohoku University |
| Konferenzangaben | 8th International Symposium on Measurement Technology and Intelligent Instruments, Sendai, 24-27, September, 2007, Japan |
| Freie Schlagworte | optical metrology ; dimensional measurement ; interferometry ; refractive index ; Edlen formula |
| Zusammenfassung | A well known method for compensation of the refractive index of air for length measurements baced on the speed of hight is a measurement with two different wavelengths and using the dispersion relation. No measurement of temperature, pressure, and C02 content of the air is necessary. However, this method is valid only for dry air and is practically not used to our knowledge. We investigated a modified compensation method where the air pressure and the humidity are measured conventionally. The effective temperature in the measurement path which is necessary to calculate the refractive index is derived from the length results for both wavelengths. Our experiments indicate a length dependent measurement uncertainty of below 2.5 × 10-7 L for distances up to 50 m. |
