Delay Interval : The nominal time between the detonations of delay detonators of adjacent periods in a delay series; the nominal time between successive detonations in a blast
United States Mine Rescue Association USMRA (membership,mine rescue and safety training resources, and mine disasters and accidents), Mine Safety and Health Quizzes, Glossary of Blasting Terms, PA,USA 2016. http: //miningquiz.com/pdf/Glossaries/Glossary_of_Blasti ng_Terms.pdf, (Blasting - Amer) {997}