The 4.5 kg " Standard" Clegg Impact Soil Tester was the first Clegg Hammer developed by Dr. Baden Clegg in the 1970' s. It was initally concieved for basecourse testing but has turned out to be the general purpose Clegg. It is based on the instrumentation of a " modified proctor" labotratory compaction hammer.
The Hammer mass is 5 cm in diameter at 4.5 kg and is dropped from a set height of 45 cm. The weight of the guide tube and metre is approximatley 2 kg. The Australian shipping case weighs approximatley 6 kg. The total weight is around 13 kg. Instrument height is 70 cm and the guide tube is 15 cm in diameter. The shipping case is around 25 cm by 25 cm by 80 cm. The output at the fourth drop of the standard Hammer when dropped from its standard height is known as the Clegg Impact Value ( CIV) .