SD Instrumentation Index

SD Instrumentation are the manufacturers of the Clegg Impact Soil Tester range - an instruments that provides a means for the measurement and control of soil strength and consolidation levels, during the process of re-instating trenches.

The range of products is also used to ensure for the confirmation of uniform compaction over wide areas of ground. This can help ineffective rolling of materials and identify poorly compacted areas. The most popular SD Instrumentation tool is one which uses a 4.5kg hammer.

SD Instrumentation offer more than just 4.5kg versions. SD Instrumentation also offer models for 0.5kg and 2.25kg for use on sports turf and golf course fairways. There are also larger 10kg and 20kg models, for use in testing roadworks and harder materials.

Each instrument consists of a vertical guide tube, containing a compaction hammer, which operates inside. From a fixed height, the hammer is released and it falls through the tube and strikes the surface under the tester. This process decelerates at a rate set by the stiffness of the material within the area of impact. Then, a precision accelerometer (which is mounted on the hammer) sends it's output to a handheld digital readout unit, which gives you the deceleration rate (in units of impact value, known as IV). The IV number indicates the strength of the soil and shows good correlation with the CBR test results.

SD Instrumentation has a policy of continual development and improvement, and has also been registered to Quality Assurance Standard BS EN ISO 9001: 2008.

CIST/882

CIST/883

CIST/884