Hjelmstad, Kenneth E. <br/><br/>
Effect of ultralow frequency signaling on blasting array current 

 - Washington, DC :  U.S. Dept. of the Interior, Bureau of Mines,  1993 
 - 7 p. :  il 
 - Report of investigations / United States of the Interior, Bureau of Mines  ; 9479 .
<br/><br/>p. 7 
<br/><br/><label>Subjects--Topical Terms: </label><br/>ALARMA CONTRA INCENDIOS<br/>DETONADORES ELECTRICOS--MEDIDAS DE SEGURIDAD<br/>ONDAS ELECTROMAGNETICAS--TRANSMISION
<br/><br/><label>Dewey Class. No.: </label>622.23  / H672