30 CFR §57.6407

1. (a)In surface operations—
   1. (1)Continuity of each electric detonator in the blasthole prior to stemming and connection to the blasting line;
   2. (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. (3)Continuity of blasting lines prior to the connection of electric or electronic detonator series; and
   4. (4)Total blasting circuit resistance prior to connection to the power source.
2. (b)In underground operations—
   1. (1)Continuity of each electric detonator series; and
   2. (2)Continuity of blasting lines prior to the connection of electric or electronic detonators.