title: Apparatus to measure adsorption of condensable solvents on technical surfaces by photothermal deflection.
abstract: This article describes an instrument for the measurement of the mirage effect as a tool to determine the molar adsorption per unit surface area Y(1) of condensable solvents in the presence of a non-condensable carrier gas. The present apparatus is a much improved version of previous prototypes developed in our laboratory and elsewhere with a higher surface bake-out temperature (150 °C rather than 40 °C), lower residual vacuum (3 Pa versus 100 Pa), greater sample surface (40 mm diameter instead of 10 mm), more powerful optical pump beam (150 W cf. 50 W), and larger saturated vapour preparation volume (4 L instead of 1 L). The new set-up also includes the in situ monitoring of the surface via a reflected HeNe laser beam for the real-time detection of the onset of condensation. Here, we give a detailed description of the various components, outline the experimental procedure, show typical results, and suggest some straightforward improvements.
authors.affiliation: Laboratoire commun de métrologie, LNE-CNAM, 61 rue du Landy, F-93210 La Plaine Saint-Denis, France. mark.plimmer@cnam.fr
authors.forename: M D
authors.initials: MD
authors.lastname: Plimmer
authors.forename: D
authors.initials: D
authors.lastname: du Colombier
authors.forename: N
authors.initials: N
authors.lastname: Iraqi Houssaini
authors.forename: Z
authors.initials: Z
authors.lastname: Silvestri
authors.forename: P
authors.initials: P
authors.lastname: Pinot
authors.forename: R
authors.initials: R
authors.lastname: Hannachi