Window sampling is a technique whereby small diameter cylindrical steel tubes (with cut out windows) are driven into the soil with a mechanical (petrol, electric or hydraulic) hammer and extracted manually or hydraulically. The samplers will show a virtually undisturbed horizon for logging and (sub) sampling.
Window sampling can be used for a range of investigations, including for contaminated land, geotechnical investigations and for the installation of ground gas and ground water monitoring wells
Such rigs are good for investigating areas where access is limited. In addition to the standard window sampling machines, modular and hand-held equipment is available for difficult access such as embankments or basements. Electric rigs are also available for use in areas that may be sensitive to fuel exhaust and/or do not have suitable access for ventilating exhaust fumes.
The equipment is track mounted and is capable of carrying out in situ testing, including SPT/CPTs and dynamic probe testing. Dynamic Probe testing is a continuous soil test procedure which enables the relative density or strength of the ground to be inferred.