This equipment is used to determine grade of bitumen. Penetration tests are being conducted to find out consistency of bitumen for grading purposes. Penetration for gradation is determined in terms of depth of 1/10 of millimeter to which a standard needle of standard weight penetrates vertically in course of five seconds at a temperature of 25 º C.

Salient Features

Popular features of standard penetrometer are :

• The apparatus consists of a vertical pillar affixed on a base provided with leveling screws.
• The head of the apparatus, along with dial plunger rod and cone slides on a pillar that can be mounted at any desired height.
• A rack, pinion and pointer assembly provides adjustment of needle or cone tip to sample.
• This assembly incorporates a clutch mechanism, which makes reading of penetration and consequent resetting of a simple and accurate process.
• The dial plunger is graduated into 400 1/10 of a millimeter subdivisions.
• The apparatus is provided with bitumen penetration needle, two ring weights, one of 50 gm and other of 100 gm weight; and two sample containers.

Accessories of Standard Penetrometer

Accessories supplied with the Penetrometer apparatus are :

• Penetrometer Cone, made of gunmetal and is fitted with a hardened and ground detachable steel, tip and a stem. The cone is used for empirical estimation of penetration of lubricating grease, petroleum jelly etc.

Besides, the above mentioned apparatus, there is an Automatic Standard Penetrometer available in the market for bitumen testing.

Applications

Penetrometer is mainly used to determine grade of bitumen. Some other fields, where it finds application are :

• Geotechnical Studies
• Soil Study
• Construction (Buildings, Bridges, Dams, etc.)
• Petroleum Industry
• Highway Design & Construction