Patent ID: 7891233

Claim:
A blast movement monitor for measuring the movement of material within a body of material as a result of a blasting operation, the monitor including: a housing having an interior chamber defining an inner surface; and an internal communication device that is received immediately within the interior chamber of the housing, the internal communication device including: a cylindrical body portion; an end portion formed integrally with one end of the body portion in order that the end portion and body portion define a cavity that is closed at one end by the end portion an electric coil wound around the body portion; a circuit board electrically connected to the coil; a battery electrically connected to the circuit board; the battery and circuit board being housed within the cavity; and a cap associated with an opposing end of the body portion that encapsulates the body portion and sealingly houses the body portion thereby insulating the body portion, electric coil, circuit board and the battery from the external environment; wherein the internal communication device is biased to facilitate self-righting of the internal communication device to a desired orientation within the interior chamber independent of the orientation of the monitor.