zweikammerige luftdichte, verschließbare Glasschale, die vielfältige Anwendung zur quantitativ-analytischen Erfassung von gasfreisetzenden Substanzen nach der Mikrodiffusionstechnik findet
The technique employs a special microdiffusion dish, variously termed a Conway cell, Conway dish, Conway unit, or Conway vessel. This consists of a shallow circular glass vessel, 40–70 mm in diameter, containing a central well and with a closely fitting lid sealed with grease; the lid closes the outer annular space but does not touch the wall of the central well. The sample is placed in the outer annulus, and a gas‐absorbing reagent is placed in the centre well. The specific reagent is added to the sample, the lid is closed, and diffusion of the evolved gas allowed to proceed. Subsequently the remaining gas‐absorbing reagent is titrated.
Pipette 1 ml of the boric acid indicator solution (4.2) into the inner chamber of the Conway flask (5.3) and wash the residue liquid from the evaporation process (6.1) into the outer chamber. Slightly tilt the Conway flask and add about 1 ml of the potassium hydroxide solution (4.3) to the outer chamber as quickly as possible but as far from the majority of the liquid in the outer chamber as possible. Immediately seal the Conway flask by covering with a tightly fitting lid smeared with grease.
