The principle behind the Clegg Impact Soil Tester, also called the Clegg Hammer and Clegg Decelerometer is used to obtain a measurement of the deceleration of a free falling mass (Hammer) from a set height onto a surface under test to determine hardness. The impact of the hammer produces an electrical pulse, which is converted and displayed on the Control Unit in units of gravities "G-max" or tens of gravities "CIT". Reference ASTM test methods D5874 and F1702.

The standard test protocol developed by Dr. Clegg is to drop the hammer four consecutive times on the same location with the highest value result in the series taken as the Peak Clegg Impact Test result. Since that time, other test protocols have been used based on the materials under test and the application. These other protocols like the ones used for testing artificial turf test the area with a single drop. The Clegg offers the convenience of rapidly scanning compaction variation over large areas.  In research studies, 250 tests were performed with the Clegg in a half-day.

The NEW PNCLEGG-S-2.25-A- Clegg Impact Tester 2.25 kg model reads out from 0 to 150 Gravities or 0 to 15 CIT's and has a better accuracy range as compared to the 0-1000 Gravity unit for testing soft surfaces like natural and artificial athletic fields, infill products and sports fields.  This model is the same model that is used to test all NFL Stadium Fields before games.  Instruction manual comes with conversion formula to convert readings to F355 readings.

Available in following models.

• 0.5 kg - Used for soft turf, sand areas and golf greens (0 to 1000 Gravities)
• 2.25 kg - Used for surfaces consisting of natural or synthetic turf (football, baseball, soccer fields, playgrounds, pitches, horse tracks, and golf greens). (0 to 1000 Gravities)
• 2.25 kg-A - New Used for surfaces consisting of natural or synthetic turf (football, baseball, soccer fields, playgrounds, pitches, horse tracks, and golf greens). (0 to 150 Gravities) New
• 4.5 kg - Used for surfaces such as preconstructed soils, trench reinstatement, bell holes, and foundations
• 10 kg - Used for flexible pavement, aggregate road beds, trench
  reinstatement, bell holes, and foundations.
• 20 kg - Used for surfaces such as flexible pavement, aggregate road beds, trench reinstatement, bell holes, and foundations.

Simple and quick test procedure

1. The test procedure is very rapid and can easily be performed by site personnel with minimal training. Each test can be completed in less than 30 sec. The results are immediate.
2. Select a level surface (If needed, lightly scuffing surface with a foot to level the strike area)
3. The guide tube is set into position, secure by placing a foot on the tube's base flange and steadied with the lower leg and knee)
4. The ON/RESET button on the control box is pressed and release to activate the circuitry. The hammer is raised to the drop height indicator mark
5. The level is centered.
6. The hammer is released allowing it to fall freely and cleanly
   Without moving the guide tube or pressing the ON/RESET button, the Hammer is raised to the mark and release
7. The gravities value (Gmax) or CIT value is displayed after the fourth blow is recorded and the display automatically powers down 30 sec. after activation
8. Move to the next test site.

Also see our infill depth gauges for accurate and consistant depths of infill materials
Turf-Tec Professional Model Infill Depth Gauge
Turf-Tec Professional Model Infill Depth Gauge for synthetic turf