Optimization of blast operation
V.O.D and timing are the two physical levers a blaster controls. Measuring them turns blast design into a quantitative engineering process.
What V.O.D controls in a blast
V.O.D defines how the energy stored in the explosive is partitioned between shock energy, which fractures the rock, and heave energy, which displaces the broken rock. A higher V.O.D shifts the balance towards shock energy and finer fragmentation. A lower V.O.D shifts it towards heave, which is useful for cast blasting or coal recovery.
Real V.O.D values in the blast hole depend on diameter, confinement, density, water content and initiation quality. Published catalog values are a starting point, not a guarantee. Measuring V.O.D in operating conditions is the only way to confirm that the explosive performs as designed.
What detonator timing controls ?
The detonation sequence governs how holes interact. Correct inter hole and inter row delays let each hole free face the next one, allowing efficient rock movement and limiting vibration peaks. A drift of a few milliseconds can re collide rock columns, increase backbreak, generate flyrock or amplify ground vibration on nearby structures.
Measuring the actual delay times of detonators prior to a critical blast ensures that the selected batch is operating in accordance with specifications. This also enables the detection of the effects of ageing on pyrotechnic delay elements and confirms the programming of electronic detonators.
A measurement based optimization loop
Baseline. Measure V.O.D in representative holes and measure the actual delays of the chosen detonator lot.
Establish correlations. Compare the measurements with fragmentation, the profile of the excavated rock, vibration records and projection observations.
Adjust. Modify the explosive selection, density, hole diameter, decking, timing or detonator class.
Re measure. Confirm that the new design returns the expected V.O.D and timing before scaling up.
The loop turns blasting from a recipe into a quantitative process tied to measurable outcomes such as drilling cost per tonne, fragmentation passing size and vibration compliance.
Kontinitro instruments for the loop
For V.O.D in the blast hole, the Explomet 4 paired with the EasyProbe System records up to five V.O.D measurements per blast over a 4.5 meter probe length, in dry or wet holes. For delay verification, the Detomet 4 measures one to five detonators per shot with a timing precision of 0.01 microsecond.