CFR › Title 30 › Part 7 › §7.6530 CFR §7.65Verified against eCFR.gov as of June 20, 2026View official text on eCFR.gov ↗Copy linkThe following critical characteristics shall be inspected or tested on each blasting unit to which an approval marking is affixed:(a)The output current.(b)The voltage cut-off time.(c)The components that control voltage and current through each making and breaking electric contact.(d)Operation of the visual indicator and the firing switch.