reservoir 70 is designed to substantially wrap around the liquid column 38 the irrigation pipe 68 has at its top end means to attach to a source of liquid to be pumped into the irrigation pipe 68 and the reservoir 70 the attachment means is typically that of threaded grooves adapted to accept a barb 72 the barb 72 has grooves designed to screw into the top of the irrigation pipe 68 forming a liquid tight seal the barb 72 is further adapted to attach to a hose faucet or other source of liquid liquid typically water is pumped into the barb 72 and down the irrigation pipe 68 into the reservoir 70 in operation the wedge 10 is placed onto the surface of the material to examine and the liquid is pumped into the irrigation system as the analysis of the material commences the wedge 10 is slowly moved down the surface of the material being tested the irrigation system allows liquid to be pumped into the wedge and to seep out around the interface of the wedge 10 with the material being analyzed this has a coupling effect and aids in the measurement and detection of flaws the liquid is pumped into the irrigation system at a rate such that the liquid slowly seeps out from under the wedge 10 between the base.