(b) A Brass Screw Cap, to connect the upper part of the body
of the filter unit (see 6.1.8.2) to the lower part of the pipet (see
6.1.8.1) to ensure a leak-free joint. An example of satisfactory
connection is shown in Fig. 7.
(c) A Disc, 15 6 0.1-mm diameter, of plain weave stainless
steel wire mesh gauze with a nominal aperture size of 45 µm.
The nominal diameter of the wire shall be 32 µm, and the
tolerance for the size of an individual aperture shall be as
follows:
(1) No aperture size shall exceed the nominal size by more
than 22 µm;
(2) The average aperture size shall be within 6 3.1 µm of the
nominal size;
(3) Not more than 6 % of the apertures shall be above the
nominal size by more than 13 µm.