Investigation of tunable diode laser absorption spectroscopy for its application as primary standard for partial pressure measurements

Abstract

Partial pressures in vacuum systems can be quite accurately measured by tunable diode laser absorption spectroscopy in the infrared. To examine the possibility for its application as primary standard, for CO2 in the 2-μm-region we made full traceability to the respective SI unit for each input quantity of the model, evaluated the results according to the ISO guide to the expression of uncertainty in measurement, and validated the method successfully by comparison with gravimetrically produced samples of CO 2 in N2. © 2008 IOP Publishing Ltd.