The softening point is the temperature at which the substance attains particular degree of softening under specified conditions of test. For Bitumen, it is usually determined by Ring and Ball test.
The instrument conforms the requirements of IS:1205 and consists of:
Two steel balls, each having a diameter of 9.5mm.
Two tapered rings, made of brass having depth 6.4mm, ID at top 17.5mm, ID at bottom 15.9mm and OD 20.6mm.
Two ball centering guides.
One ring holder.
One Borosil glass beaker having ID 8.5cms and depth 12cms approx.
One hand stirrer.
Two thermometers 0-110°C having a least count of ½ °C.
Supplied as above without heating device.