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Effect of Ultralow Frequency Signaling on Blasting Array Current.

PB94112414

Publication Date	1993
Personal Author	Hjelmstad, K. E.; Griffin, R. E.
Page Count	13
Abstract	The U.S. Bureau of Mines (USBM) has developed an electromagnetic (EM) fire warning alarm system for underground mines. The system generates a magnetic field for through-the-earth signal transmission to microreceivers carried by individual miners. EM fields can induce electric currents in metallic conductors; if an EM transmitting antenna and an electric blasting cap array are too close, the field could induce a current in the blasting array and cause zn unintentional initiation of the electric detonators. The USBM conducted tests that define the safe and unsafe regions for using electric detonators near the transmitting antenna of the warning alarm system.
Keywords	Mine fires Underground mining Warning systems Electromagnetic radiation Antenna arrays Human factors engineering Safety engineering Ignition Explosions Blasting Caps(Explosives) Detonators Electric ignition
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries 94H - Industrial Safety Engineering 63H - Radiofrequency Detection 95D - Human Factors Engineering
Corporate Authors	Bureau of Mines, Minneapolis, MN. Twin Cities Research Center.
Supplemental Notes	Library of Congress catalog card no. 93-28949.
Document Type	Technical Report
Title Note	Rept. of investigations/1993.
NTIS Issue Number	199403

Effect of Ultralow Frequency Signaling on Blasting Array Current.

Effect of Ultralow Frequency Signaling on Blasting Array Current.
PB94112414

Publication Date	1993
Personal Author	Hjelmstad, K. E.; Griffin, R. E.
Page Count	13
Abstract	The U.S. Bureau of Mines (USBM) has developed an electromagnetic (EM) fire warning alarm system for underground mines. The system generates a magnetic field for through-the-earth signal transmission to microreceivers carried by individual miners. EM fields can induce electric currents in metallic conductors; if an EM transmitting antenna and an electric blasting cap array are too close, the field could induce a current in the blasting array and cause zn unintentional initiation of the electric detonators. The USBM conducted tests that define the safe and unsafe regions for using electric detonators near the transmitting antenna of the warning alarm system.
Keywords	Mine fires Underground mining Warning systems Electromagnetic radiation Antenna arrays Human factors engineering Safety engineering Ignition Explosions Blasting Caps(Explosives) Detonators Electric ignition
Source Agency	Bureau of Mines
NTIS Subject Category	48A - Mineral Industries 94H - Industrial Safety Engineering 63H - Radiofrequency Detection 95D - Human Factors Engineering
Corporate Authors	Bureau of Mines, Minneapolis, MN. Twin Cities Research Center.
Supplemental Notes	Library of Congress catalog card no. 93-28949.
Document Type	Technical Report
Title Note	Rept. of investigations/1993.
NTIS Issue Number	199403