Blast Training International

Ohms is a measure of the electrical resistance of a circuit.

To calculate the resistance of a firing cable you need to know the length of the cable and the number of ohms per 100m.

Example if a firing cable is 1,600 meters long with a resistance of 1.4 ohms for every 100m the resistance is 16 x 1.4 = 22.4 ohms

The symbol for ohms is Ω

Detonating cord with an outer wrapping of spun yarns.

Overwrapped cord has a braided appearance and is easier to tie knots in.

Overwrapped cord.

Plastic finished cord.

High temperature detonating cords are limited by the explosives properties and the jacket material.

Chemically – the gain of oxygen by a molecule, atom or ion.

O2 Balance refers to the balance between the oxidiser and the fuel in an explosive.

Oxygen balanced explosives are mixed such that all the oxidiser and the fuel are used up in the detonation.

Where explosives are not O2 Balanced a reduction in energy and an increase in blast fume are likely outcomes.