CFR > Title 30 - Mineral Resources > CHAPTER I—MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR > SUBCHAPTER B—TESTING, EVALUATION, AND APPROVAL OF MINING PRODUCTS (parts 5 to 36) > PART 7—TESTING BY APPLICANT OR THIRD PARTY > SUBPART D—Multiple-Shot Blasting Units (§7.61 to §7.72) > 7.65—Critical characteristics.

7.65—Critical characteristics.

The 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.