Abstract:
A sensor module (110) includes a module case (112) coupled to a module cap (114). The module cap (114) provides an access into the module case (112) for one or more electrical conductors of a telemetry cable. Housed in the module case (112) and module cap (114) is a sensor electronics package (116), the module case (112) is constructed with a wall thickness that allows for wall flexure to provide damping of high-g shock input. The outer surface (126) may include a longitudinal ridge (128). The longitudinal ridge (128) provides a key-type fit to prevent inadvertent rotation after the sensor module (110) is inserted into the ground. Disposed between the module tip (120) and the sensor electronics package (116) is an isolator (115) for isolating the sensor electronics package from damaging mechanical shock axially induced in the sensor module (110). The isolator (115) may comprise one or more layers (115a) and (115b) of vibration-isolating material. A first isolating layer 115a adjoins the electronic package 116 and a second isolating layer (115b). The second isolating layer (115b) adjoins the first isolating layer (115a) and the module tip (120). The first isolating layer (115a) is manufactured from a material such as silicone, and the second iasolating layer (115b) is manufactured from a material such as high-damping polyurethane foam. A second, and similary constructed isolator (130) is disposed between the sensor electronics package (116) and the module cap (114). The sensor module (110) includes one or more MEMS accelerometers in an electronic package (116).