NONEL MS is a conventional initiation system with 25 ms delay time between each period number. The short delay times remains from the times when small diameter blastholes and small burdens were predominent Drill series 11 and 12 give burden distances of 1.0 to 1.5 m and then a delay time of 25 ms between the rows is suitable. NONEL MS is used in bench blasting , underwater blasting and sublevel stoping. NONEL UNIDET is an initiation system with uniform delay time in the blasthole detonator and variable delay time on the surface. The delay time in the blasthole is normally 500 ms (other delay times may be chosen), Then the firing sequence is built up on the surface with connecting units with their own delays. Surface delay units are available with delay times from 0 ms to 285 ms which gives greater flexibility to adapt the firing sequence to burden distance and rock conditions. NONEL LP is an initiation system developed for underground operations. The delay times are generally longer to give the blasted rock time enough to move forward in the confined spaces that are prevailing in tunnel blasting.Â¨ NOTE! Detonators intended for blastholes may not be used at the rock surface.