CROSSHOLE SEISMIC EQUIPMENT

This equipment, designed to work in 100 mm (4 in.) I.D. casings, has a proven record through many years of use. The hammer has gripper plates that expand out to make firm contact with the inside of the casing. The sensor is placed and positioned with hanger bars allowing accurate orientation in the receiver casing. The sensor housing has an expandable bladder that fixes the sensor at the proper elevation. The trigger is located in the hammer and each sensor has 3-axis measurement capability. The manifold unit is designed to accommodate up to four sensors. The equipment has many other design features which facilitate accurate shear wave velocity measurements in accord with procedures described in ASTM D 4428/D 4428M.