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Clegg Impact Soil Tester

The Clegg Impact Soil Tester provides a means for measuring and controlling soil strength and consolidation levels during trench re-instatement. It is also used to confirm uniform compaction over wide areas of ground, identifying poorly compacted areas and ineffective rolling of materials. A special lightweight version of the Tester is also available for checking sports turfs whilst a heavy duty version is supplied for testing harder materials and roadworks.(Enquire)
The Clegg Impact Soil Tester provides a compact and reliable instrument for monitoring and controlling the quality of reinstatements while the work is in progress, avoiding the need for re-excavation should later tests reveal poor workmanship.

The Clegg Impact Soil Tester consists of a 4.5 kg compaction hammer operating within a vertical guide tube. When the hammer is released from a fixed height, it falls through the tube and strikes the surface under test, decelerating at a rate determined by the stiffness of the material within the region of impact. A precision accelerometer mounted on the hammer generates an electrical charge which is fed by a cable to a hand-held digital readout unit. The readout unit scans and filters the signal and registers the deceleration in units of Impact Value (IV). The Impact Value is an indication of soil strength and shows good correlation with results from CBR tests.
Data from the Clegg Impact Soil Tester can therefore be used in a similar manner to results from CBR tests performed in the laboratory and in the field.
We also manufacture versions that use heavier hammers. These instruments are supplied with a 10 Kg or a 20 Kg Hammer mounted within a metal guide tube on a pull along cart. Please enquire for more details.


The Clegg Impact Soil Tester has been approved by the American Society for Testing and Materials and a Standard, under Designation No D 5874 was issued in 1995, entitled “Standard Test Method for Determination of the Impact Value (IV) of a Soil”.


Technical specifications are subject to change without notice.

Model CRT-CIST-882 CRT-CIST-883 CRT-CIST-884
Basic Model With Data Logging With Data Logging
and GPS
Hammer Weight (Kg) 4.5 4.5 4.5
Readout Display Backlit vertical display.Hand Held Readout Unit – Easy to view. Vertical display with readout unit clamped to Guide Tube – Easy to view. Backlit vertical display. Readout unit clamped to Guide Tube – Easy to view.
Readout Range upto 101 Impact Values (IV)
Power Source 9V ‘PP3’. Low power 3V: From two ‘AA’ Cells. Low power 3V: From two ‘C’ Cells.
Battery life 12 Month 12 Month 12 Month
Battery level at switch-on X
Power ‘On’ & Controls Single push button. Button held during site measurement. Single push button. Auto switch off after 5 minutes from last reading Single push button. Auto switch off after 5 minutes from last reading
Data Storage in Readout X
Bluetooth™ Wireless data transfer X
Data output in Excel™/KML files X
Integrated GPS X X
Readout Displaying %CBR Can be fitted
System software for real time test view/configuration set-up X
Transit & Storage Case
Dimensions mm 710 x 130 x 130 710 x 130 x 130 710 x 130 x 130
Instrument Weight (Kg) 6.9 6.8 6.9
Packed Weight in case (Kg) 12.2 12 12.2