Sensors deployed in natural environments, such as rivers, beaches and glaciers,\r\nexperience large forces and damaging environmental conditions. Sensors need to be robust,\r\nsecurely operate for extended time periods and be readily relocated and serviced. The\r\nsensors must be housed in materials that mimic natural conditions of size, density, shape and\r\nroughness. We have developed an encasement system for sensors required to measure large\r\nforces experienced by mobile river sediment grains. Sensors are housed within two discrete\r\ncases that are rigidly conjoined. The inner case exactly fits the sensor, radio components\r\nand power source. This case can be mounted within outer cases of any larger size and can\r\nbe precisely moulded to match the shapes of natural sediment. Total grain mass can be\r\ncontrolled by packing the outer case with dense material. Case design uses Solid-WorksTM\r\nsoftware, and shape-matching involved 3D laser scanning of natural pebbles. The cases\r\nwere printed using a HP DesignjetTM 3D printer that generates high precision parts that lock\r\nrigidly in place. The casings are watertight and robust. Laboratory testing produces accurate\r\nresults over a wider range of accelerations than previously reported.
Loading....