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 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]