The apparatus consists of 4 parts. A water bath with 500 watt heater covered 1000 mI. vessel made from Borosil glass and digital temperature control. Variable speed motor, with 30cms longs stainless steel shaft. A cylindrical stainless steel basket and a membrane fixing attachment, water bath is made of imported thick Acrylic sheet with transparent cover at top. Temperature of the bath is maintained at 37°C with an accuracy of ±1° C.A cylindrical glass vessel of 1000 ml. capacity with slightly concave bottom has a flenged edge at the top to accept a fitted cover having four holes. One hole placed in the centre. The shaft of the motor is fitted on an up right and has an electronic speed regulating device that allows the speed to be varied from 25 to 250 R.P.M. The shaft is 6 mm dia. 30 cms on with basket fitted at end rotates smoothly and without any significant wobble. The basket consist of two parts one of which is attached to the shaft. It is of solid metal except for 2 mm vent and is screwed on the main shaft.Lower part of the basket is held with this part by means of threading and this allows proper removal of lower part for introduction of the test samples. The detachable part of the basket is fabricated of stainless steel mesh formed into cylinder of size 36 mm x 25 mm dia. The equipment is workable on 220 volts 50 C/S A.C. (b) -do- same as above but Analog type single stage. (c) -do- same as above analog type double,three & Six Stage.