Dr Baden Clegg (b.1925-d.1999) originated the concept of the Clegg Impact Test in the late 1960’s while a lecturer at the University of Western Australia in Nedlands (Perth) Western Australia. The idea occured to him that by instrumenting a laboratory compaction hammer it might be possible to obtain a parameter relating to the strength/stiffness of soils and soil-like material. Initial experiments on basecourse materials proved promising and under Dr Clegg’s guidance, the test method and apparatus (the Clegg Impact Soil Tester) were developed.

The parameter obtained was called by the University the Clegg Impact Value (CIV) in recognition of Dr Clegg and so as to distinguish it as a value derived from the test method he developed.

In the mid 1980’s, the University transferred the rights of the concept to Dr Clegg as part of his retirement after around thirty years as lecturer with the University in their Department of Civil Engineering. Around this time, Dr Clegg formed agreements with several companies around the world regarding manufacture under licence of the Clegg Impact Soil Tester (or Clegg Hammer as it is also called).