Clegg Hammer - Impact Soil Tester Type With Fitted GPS

Clegg Hammer - Impact Soil Tester Type With Fitted GPS

The Clegg Impact Hammer with GPS can be used to measure the hardness or shock absorption properties of a many sports surfaces. The integral GPS is a useful feature for ensuring the spatial consistency of pitches and other surfaces, identifying problem areas and taking repeated measurements over time.

The Clegg Impact Hammer with GPS is particularly suitable for winter sports pitches, cricket pitches and equestrian surfaces.


Clegg Impact Hammer Soil Tester Type With GPS for Winter Sports, Cricket and Equestrian - 2.25 kg


A Clegg Impact Hammer is a useful instrument to enable the preparation of quality and consistent playing surfaces in many sports. It can be used to aid decisions relating to playing surface quality, safety and turfgrass health. The Clegg Impact Hammer soil test is simple to undertake and easily reproduceable delivering straightforward and unbiased results.

The Clegg Impact Hammer has been used successfully for many years for testing the hardness of American Football pitches. The results have been demonstrated to correlate closely with head injury severity indexes and are therefore used to aid decisions relating to safety.

Winter sports which have a risk of injury to hard ground can similarly take advantage of the unbiased results provided by the Clegg Impact Hammer to aid decisions relating to safety. In addition, the test can be use

Firmness tests using Clegg Impact Hammers are used in golf to aid the assessment of greens playing qualities relating to ball impact, bounce and spin. Firmer surfaces are associated with a fair but challenging game that is rewarding to accurate play.

In cricket the Clegg Impact Hammer soil test is a good predictor of both bounce and pace. This makes it a useful addition for an unbiased determination of playing surface quality.

Table 1: Use of Clegg Impact Hammer soil test on different sports surfaces+

Surface Drop Height (mm) Target Reading (g*) Source
Cricket Pitch 450 360 ECB
Winter Sports 450 70 - 90 UEFA

+ The Clegg Impact Hammer can also be used on other types of surface (e.g. tennis courts, bowling green, equestrian surfaces etc.)
*Acceleration due to gravity.

The Clegg Impact Hammer can also be used to assess surface consistency throughout the year as well to ensure that different areas of a surface will deliver comparable playing conditions. This requires multiple measurements to be made across the surface of the pitch to calculate the degree of variation between measurements. The Clegg Impact Hammer with fitted GPS will enable measurements to be linked to location enabling greater confidence in identifying areas which require treatment and ensuring that assessments of surface hardness over time are taken in the same locations to increase the reproducibility and robustness of results.

Table 2: Suggested number of measurements to test for consistency

Surface Number of Locations
Cricket Pitch 20+
Winter Sports 20 - 70
Golf Greens 5 -20


Operating Principle:- The Tester consists of a 2.25 kg compaction hammer operating within a vertical guide tube. The Hammer falls through the tube when released and strikes the surface under test, decelerating at a rate determined by the stiffness of the material within the region of impact. The readout registers the hardness values in units of Gravities (Gm). The Gm value is an indication of soil strength.

Design:- The Clegg Impact Hammer Soil Tester is a very rugged design suitable for prolonged use in damp, dirty and harsh site environments. The CIST/883 readout unit is made from high strength alloy that has been proven to last for decades. The CIST/883 Clegg Impact Soil Tester is a compact and reliable instrument. A Transit & Storage Case is included. The Clegg Impact Hammer with GPS also features automatic GPS measurements to provide latitude and longitude location information.

Test Procedure:- Carrying out a test is quick and straightforward. The guide tube is placed in position vertically on the surface to be tested. The digital readout is located on the guide tube during testing allowing easy use as there is no need to hold the readout in the hand. The hammer is raised to the desired height and then allowed to fall freely. This procedure is repeated three times. The reading achieved on the third drop being recorded as the measurement value. The test data is recorded in the instrument and it is downloadable to a computer wirelessly by Bluetooth.

Features of the Clegg Impact Hammer Soil Tester Type With GPS for Winter Sports, Cricket and Equestrian

Hammer Weight 2.25 kg
Readout Display Easy to view backlit vertical display clamped to Guide Tube.
Readout Range Up to 800 Gravities (Gm)
Power Source Two 'C' cells. 12 month typical battery life.
Battery Life Up to 12 months
Data Storage in Readout Flash memory for ~10,000 drop tests. Each stored field contains the time and date of the test, firmness and the latitude, longitude and number of satellites.
Data Transfer Method BluetoothTM Wireless data transfer to PC or laptop.
Data Files when Transferred Comma Separated Variable (CSV) data for manipulation in 3rd party packages such as ExcelTM and KML readable by e.g. Google EarthTM. Viewable directly in Google MapsTM. Calculates and stores Ordnance Survey GB Eastings and Northings.
Transit & Storage Case Aluminium Case
Size & Weight (approx). 83 x 31 x 28 cm.
Instrument Weight: 6.9 kg
Packed weight in case: 12.2 kg
GPS Accuracy / Output Typically < than 5 metres.
Google MapsTM, Google EarthTM and Ordnance Survey GB Easting and Northing to 1 m res. (e.g. "ST 8026955704" & "E380269 N155704").

For any further information on the Clegg Impact Hammer Soil Tester Type With GPS for Winter Sports, Cricket and Equestrian - 2.25 kg, please contact a member of our technical sales team on 01902 440250.