Two families of detonators
Civilian and industrial blasting uses two main detonator families. Pyrotechnic detonators rely on a combustible delay element whose burning time defines the delay. Electronic detonators replace the delay element with a programmable electronic timer driven by an integrated circuit.
Both families are initiated through a shock tube, an electric line or a wireless system. Once the initiation signal reaches the detonator, a measurable interval passes before the base charge detonates. That interval is the detonator delay.
Why delays must be measured
Blast design relies on precisely timed detonations to control fragmentation, ground vibration, airblast overpressure and throw. A drift of a few milliseconds across a sequence can re collide rock columns, increase backbreak or cause flyrock. Even a few percent error on a key hole can change the outcome of a tunnel face advance.
Manufacturers measure delays to validate production, document conformity and audit shelf life. End users measure delays of representative lots before critical blasts, especially when working close to sensitive infrastructure.
Measuring shock tube speed
The shock tube is itself a timing element. Its signal travels at a finite speed, typically between about 1,800 and 2,200 meters per second, but the actual speed in a specific roll or installation may deviate from the published value. Measuring it removes a hidden source of error from any delay calculation. Kontinitro Detomet 2.0 supports this measurement directly.
The Kontinitro approach
The Detomet 2.0 measures the delay of one to five non electric or electric detonators initiated by shock tube, with ±0.01 microsecond precision. Fiber optic sensors detect the light flash at initiation and at detonation, and the unit returns the interval directly. The graphical display allows configurable preliminary review, and all results are stored on SD card.
For larger campaigns, the Detomet High Capacity system extends the same architecture to 20, 24 or 30 channels in a heavy duty transport case. See the underground excavation and tunnels page for a typical deployment context.
FAQ
What is a detonator delay?+
The delay is the time interval between the input signal reaching the detonator, typically through a shock tube or an electrical line, and the actual detonation of the base charge. Delays are how blast designers stagger holes to control fragmentation, vibration and throw.
Why measure detonator delays?+
Nominal delays are nominal. Pyrotechnic delay elements are subject to manufacturing tolerances, aging and storage conditions, and electronic detonators have a programming and trigger tolerance. Measuring actual delays allows manufacturers to validate quality, and end users to audit lots before critical blasts.
How is the delay measured?+
An optical or electrical sensor detects the initiation signal, then a second sensor detects the actual detonation. The instrument records the time interval with sub microsecond precision. Kontinitro Detomet 2.0 uses fiber optic sensing of the light flash at initiation and at detonation, and returns delays of one to five detonators in a single measurement, with ±0.01 microsecond precision.
What is the actual speed of a shock tube?+
The signal speed of a shock tube is typically in the range of 1,800 to 2,200 meters per second, but the practical speed in a specific roll, batch or installation may differ from the theoretical value. Detomet 2.0 lets you measure the actual shock tube speed before using it as a timing reference.