Southwest Regional Mine Rescue Field Exam Taken from the 2019 Southwest Regional Mine Rescue Contest held in Ruidoso, New Mexico Progress Indicator: Question 5 of 30 5.  The mass of an explosive per unit of volume, usually expressed in grams per cubic centimeter or pounds per cubic foot. Choices: Institute of Makers of Explosives No. 8 test Detonator Density Instantaneous Detonator Inventory