Hjelmstad, Kenneth E.
Ultra low frequency electromagnetic fire alarm system for underground mines / by K.E. Hjelmstad and W.H. Pomroy. - Washington, D.C. (2401 E St., N.W., MS #9800, Washington 20241-0001) : U.S. Dept. of the Interior, Bureau of Mines, 1991. - 11 p. : ill. ; 28 cm. - Report of investigations / United States Department of the Interior, Bureau of Mines ; 9377 . - Report of investigations (United States. Bureau of Mines) ; 9377. .
Includes bibliographical references (p. 11).
91010026
Mine fires--Prevention and control.
Fire alarms.
ELF electromagnetic fields.
TN23 TN315 / .U43 no. 9377
622 s 622/.82
Ultra low frequency electromagnetic fire alarm system for underground mines / by K.E. Hjelmstad and W.H. Pomroy. - Washington, D.C. (2401 E St., N.W., MS #9800, Washington 20241-0001) : U.S. Dept. of the Interior, Bureau of Mines, 1991. - 11 p. : ill. ; 28 cm. - Report of investigations / United States Department of the Interior, Bureau of Mines ; 9377 . - Report of investigations (United States. Bureau of Mines) ; 9377. .
Includes bibliographical references (p. 11).
91010026
Mine fires--Prevention and control.
Fire alarms.
ELF electromagnetic fields.
TN23 TN315 / .U43 no. 9377
622 s 622/.82