| Zugriffsnummer | 13613 |
| Dokumenttyp | Zeitschriftenartikel |
| Sprache | Englisch |
| Titel | Partial pressure measurement by means of infrared laser absorption spectroscopy |
| Autor(in); Institution |
Lanzinger, Eckhard; 7.23, Vakuummetrologie, PTB-Berlin
Jousten, Karl; 7.23, Vakuummetrologie, PTB-Berlin
Kühne, Michael; 7.3, Temperatur und Wärme, PTB-Berlin
|
| Quelle/Jahr | Vacuum: 51 (1998), 1, 47 - 51 |
| ISSN | 0042-207X |
| DOI | |
| Verlag | Amsterdam [u.a.]: Elsevier |
| Zusammenfassung | Compared with the conventional method of using a quadrupole mass spectrometer, partial pressure measurement by absorption spectroscopy has the advantage of being non-intrusive: molecules are not cracked at a hot cathode, no gas molecules are produced by the instrument itself etc. We have applied tuneable diode laser absorption spectroscopy in the mid-infrared to determine absolute partial pressures of CO in the high vacuum. The sensitivity was increased by use of a Herriott multi-reflection cell. First of all, line-strengths of several rotational-vibrational transitions of CO were measured in high vacuum with a relative standard uncertainty of about 2%. The measured values agree with previously published data within their combined uncertainties. Based on these line strength values, partial pressure measurements were possible with a relative uncertainty of 3%. Our present experimental set-up allows to measure CO partial pressures down to 10-5 PA. At a total pressure of 1kPa, the highest pressure we used, this corresponds to 1 part in 108 or 10 ppb. |
