6.1 Analytical Balance, single- or double-pan, the precision standard deviation of which must be 0.07 mg or better.
6.2 Oven, of the static type (without fan-assisted air circulation), controlling to 90 6 5°C.
6.3 Petri Dishes, approximately 125 mm in diameter with removable glass supports for membrane filters.
6.4 Forceps, flat-bladed with unserrated, non-pointed tips.
6.5 Vacuum System.