7. Apparatus
7.1 General - The apparatus comprises a glass or metal still, a heater, a reflux condenser, and a graduated glass trap. The still, trap, and condenser may be connected by any suitable method that produces a leakproof joint. Preferred connections are ground joints for glass and O-rings for metal to glass. Typical assemblies are illustrated in Fig.1, Fig.2, and Fig.3. The stills and traps should be chosen to cover the range of materials and water contents expected. On assembly, care shall be taken to prevent the joints from freezing or sticking. Always apply a very thin film of stopcock grease to prevent the glassware joints from seizing.
7.2 Still - A glass or metal vessel with a short neck and suitable joint for accommodating the reflux tube of the trap shall be used. Vessels of 500, 1000, and 2000-mL nominal capacity have proved satisfactory.
7.3 Heater - A suitable gas burner or electric heater may be used with the glass still. A gas ring burner with ports on the inside circumference shall be used with the metal still. The gas ring burner shall be of such dimensions that it may be moved up and down the vessel when testing materials that are likely to foam or solidify in the still.
7.4 Glassware - Dimensions and descriptions of typical glassware for use in this test method are provided in Specification E123.
NOTE 3 - Instead of standardizing on a particular apparatus specification with respect to dimensions and style, a given apparatus will be deemed satisfactory when accurate results are obtained by the standard addition technique described in Section 9.
