The Coal and Other Safety-Lamp Mines (Explosives) Regulations 1993

Steps to be taken before firing a shot or round of shots

27.  A person shall not fire a shot or round of shots unless–

(a) where transformer coupled electric detonators are not to be used) he has–

(i) checked that all the detonators concerned are connected in series,

(ii) connected the detonator circuit to the shotfiring cable,

(iii) withdrawn himself and any person with him from the danger zone, and

(iv) tested the circuit for continuity and electrical resistance with an ohmmeter suitable for the purpose or the exploder testing circuit; or

(b) (where transformer coupled electric detonators are to be used) he has–

(i) checked that the primary looping wire has been threaded through all the toroids,

(ii) connected the primary looping wire to the shotfiring cable,

(iii) withdrawn himself and any person with him from the danger zone,

(iv) checked the circuit for electrical impedance and tested the primary looping wire and the shotfiring cable for continuity with the exploder testing circuit; and

(c) (in either case)–

(i) he has determined that the electrical resistance or impedance of the circuit is such as to make a misfire unlikely, and

(ii) it is safe to do so.