M. K. Instruments

Khokhra, ahmedabad, Gujarat

Used to determine grade of bitumen. The penetration tests determine consistency of bitumen for the purpose of grading. Depth in units 1/10 of millimeter to which a standard needle having a standard weight will penetrate vertically in a duration of five seconds at a temperature of 250C determines penetration for gradation. Two Models. Hand Operated and Electrically Operated.

Hand Operated Model:It consists of a vertical pillar mounted on a base provided with levelling screws. The head, together with dial plunger rod a cone (or needle) slides on a pillar an can be clamped at any desired height. A rack and pinion and pointer assemble provides fine adjustment of needle or cone tip to sample. It incorporates a clutch mechanism. Which makes reading of penetration and subsequent resetting a simple and accurate operation. The dial is graduated in 400 1/10 and the millimeter subdivisions and the needle pointer against figures makes easy reading. Supplied with a bitumen penetration needle, ring weight One 50gm, two sample containers.

Electrically Operated Model:Bitumen Penetrometer, Electrically operated model is provided with Automatic Digital Timer and electrical arrangement to carry out the test without needle of stop watch and with great ease and accuracy.

The apparatus can be used for three basic tests :

• Initial drying shrinkage The difference between the length of the cured specimen and the length when it is dried.
• Drying shrinkage - The difference between the length of the specimen from existing structure and its length when completely dried.
• Moisture movement - The difference between the length of the dried specimen and its length when again saturated with water.

The apparatus consists of a frame with adjustable cross plate and a recessed seating and a 300 1.0 mm long alloy steel reference bar having coefficient of thermal expansion less than 2x10-6deg with 6 mm dia steel balls mounted at the ends. Supplied complete, with a dial gauge 0.002 mm x 10 mm.

The tank has been designed to accommodate 150mm/70.6mm cube moulds upto 36/72 cube mould and fully insulated, complete with a hinged lid, heater, thermostat and re-circulated pump. Provision of two removable racks allowing free circulation of water around each mould. The pump, drain valves and electrical equipment are housed in a compartment located at one end of the tank. The Tank is heated by a immersion heater under normal conditions and refrigeration system for grey cement the temperature is controlled at 35oC or 100oC 2oC / 27oC +2oC , expect for the 15 minutes after immersion of the freshly made specimens.

• Curing Tank for 6/12 moulds of 150mm / 70.6mm size
• Curing Tank for 12/24 moulds of 150mm / 70.6mm size
• Curing Tank for 24/48 moulds of 150mm / 70.6mm size
• Curing Tank for 36/72 moulds of 150mm / 70.6mm size