appareil à aspiration d'air

CONT: Mesure de la surface foliaire. De nombreuses méthodes ont été mises au point, [...] 1. Méthodes directes. [...] Méthodes indirectes. [...] c) Interception d'un flux d'air à travers une grille. L'appareil à aspiration d'air crée une dépression manométrique, modifiée lorsque la feuille obstrue la grille; elle est rétablie par l'ouverture d'un orifice calibré.

CONT: A number of techniques for measuring leaf area have been used ... Jenkins (1959) developed a simple technique for the direct measurement of leaf area. His air-flow planimeter consisted of two identically perforated plates mounted on an air-tight drum which was connected to a blower. The air pressure of the drum was determined when the sample plate was uncovered, leaves were placed on the plate and the reference plate was then uncovered sufficiently to return to the original air pressure. The exposed area on the measuring plate was then equal to leaf area.