Abstract: A method of and apparatus for use in establishing a blasting arrangement by loading at least one detonator (14) into each of a plurality of blast holes (30), placing explosive material in each blast hole, connecting to a trunk line (10) a control unit (32) that has a power source (52) incapable of firing the detonators, sequentially connecting the detonators, by means of respective branch lines (12), to the trunk line and leaving each detonator connected to the trunk line. In addition the apparatus includes means (46, 50) for receiving and storing in memory means (34, 44) identity data from each detonator, means (46, 50) for generating a signal to test the integrity of the detonator/trunk line connection and the functionality of the detonator, and means (46, 50) for assigning a predetermined time delay to each detonator to be stored in the memory means. The invention also extends to the control unit (32).

Abstract: A blasting system wherein the actuation of detonators at a plurality of blast holes is controlled by firing one or more test blasts and, at each blast hole, monitoring the resulting shock wave to derive data which is used to determine time delay criteria for the blast holes.Each detonator includes a shock sensitive device which detects the shock wave. Each detonator has on-board signal processing capability and optionally is connected to a central control computer.

Abstract: A detonator firing element which includes a miniature energy dissipation device located on a substrate which forms part of an integrated electronic circuit. An explosive or pyrotechnic compound is exposed to the effects of energy dissipated by the device. The device may be resistive, be formed by a semi-conductor device, or be a field effect device. The integrated circuit includes timing, testing, control, communication and interlock circuits to implement stand alone or computer controlled blast systems. Protection against over-voltages and induced currents is provided. Due to the integrated circuit approach power consumption is kept to a minimum and a detonator incorporating the firing element can be powered for a substantial time period by an energy storage device such as a capacitor.