CFR > Title 30 - Mineral Resources > CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR > SUBCHAPTER K—METAL AND NONMETAL MINE SAFETY AND HEALTH (parts 56 to 58) > PART 57—SAFETY AND HEALTH STANDARDS—UNDERGROUND METAL AND NONMETAL MINES > SUBPART E—Explosives (§57.6000 to §57.6960) > 57.6407—Circuit testing.

57.6407—Circuit testing.

A blasting galvanometer or other instrument designed for testing blasting circuits shall be used to test the following:
(a) In surface operations—
(1) Continuity of each electric detonator in the blasthole prior to stemming and connection to the blasting line;
(2) Resistance of individual series or the resistance of multiple balanced series to be connected in parallel prior to their connection to the blasting line;
(3) Continuity of blasting lines prior to the connection of electric detonator series; and
(4) Total blasting circuit resistance prior to connection to the power source.
(b) In underground operations—
(1) Continuity of each electric detonator series; and
(2) Continuity of blasting lines prior to the connection of electric detonators.