A safety arrangement for a wireless blasting system which includes a plurality of wireless detonator assemblies located at a blast zone wherein each route which provides access to the blast zone is monitored to detect removal of a wireless detonator assembly which is in an operative mode from the blast zone.

A system (10) for wireless measurement of detonation of explosives (3) for detonation according to a timed sequence, the system comprising: an antenna (15, 16) for detecting electromagnetic emissions caused by detonation of the explosives and providing an electromagnetic signal representative of the electromagnetic emissions; a data logger (12) operatively connected to the antenna for logging the electromagnetic signal; a trigger for setting the data logger for logging the electromagnetic signal upon detonation of the explosives to produce a recorded blast record; and a comparison arrangement for comparing the timed sequence with the recorded blast record.

A system (10) for wireless measurement of detonation of explosives (3) for detonation according to a timed sequence, the system comprising: an antenna (15, 16) for detecting electromagnetic emissions caused by detonation of the explosives and providing an electromagnetic signal representative of the electromagnetic emissions; a data logger (12) operatively connected to the antenna for logging the electromagnetic signal; a trigger for setting the data logger for logging the electromagnetic signal upon detonation of the explosives to produce a recorded blast record; and a comparison arrangement for comparing the timed sequence with the recorded blast record.

A system (10) for wireless measurement of detonation of explosives (3) for detonation according to a timed sequence, the system comprising: an antenna (15, 16) for detecting electromagnetic emissions caused by detonation of the explosives and providing an electromagnetic signal representative of the electromagnetic emissions; a data logger (12) operatively connected to the antenna for logging the electromagnetic signal; a trigger for setting the data logger for logging the electromagnetic signal upon detonation of the explosives to produce a recorded blast record; and a comparison arrangement for comparing the timed sequence with the recorded blast record.

A system (10) for wireless measurement of detonation of explosives (3) for detonation according to a timed sequence, the system comprising: an antenna (15, 16) for detecting electromagnetic emissions caused by detonation of the explosives and providing an electromagnetic signal representative of the electromagnetic emissions; a data logger (12) operatively connected to the antenna for logging the electromagnetic signal; a trigger for setting the data logger for logging the electromagnetic signal upon detonation of the explosives to produce a recorded blast record; and a comparison arrangement for comparing the timed sequence with the recorded blast record.

A process for locating underground markers, including: transmitting signals through the ground between markers in the ground; and determining locations of the markers based on the transmitted signals.

A process for locating underground markers, including: transmitting signals through the ground between markers in the ground; and determining locations of the markers based on the transmitted signals.

A method of obtaining velocity of detonation (VOD) information from a borehole wherein an explosive in the borehole is ignited by initiation of a detonator, the method including the steps of using a control circuit which obtains a measurement of the VOD and which is subsequently destroyed by ignition of the explosive, and of transmitting from the borehole a wireless signal which contains the VOD measurement and data which identifies the borehole before the control circuit is destroyed.

A method of obtaining velocity of detonation (VOD) information from a borehole wherein an explosive in the borehole is ignited by initiation of a detonator, the method including the steps of using a control circuit which obtains a measurement of the VOD and which is subsequently destroyed by ignition of the explosive, and of transmitting from the borehole a wireless signal which contains the VOD measurement and data which identifies the borehole before the control circuit is destroyed.

A communication module which is linked to a detonator which is initiated in response to a fire command signal, and wherein the communication module includes a transmitter which transmits a wireless signal which is dependent upon initiation of the detonator and which contains or conveys an identifier which uniquely identifies the detonator.