§ 57.6407. Circuit testing.
134 words·~1 min read·
/us/cfr/t30/s§ 57.6407·A research copy — for the controlling text, always check the official state or federal source. Not legal advice.
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. \[61 FR 36801, July 12, 1996, as amended at 85 FR 2027, Jan. 14, 2020\]