Section 57.6407 - Circuit testingA 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 or electronic 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 or electronic detonators.61 FR 36801, July 12, 1996, as amended at 85 FR 2027 , Jan. 14, 2020