Section 156(8) in The Coal Mines Regulations, 2017
(8)(a)In every mine in which a mechanical ventilator is in use, the quantity of air shall, once at least in every fourteen days, be measured-(i)in every main intake and return airway of every seam or section, as near as practicable to the entrance to the mine;(ii)in every split, as near as practicable to the point at which the split commences;(iii)in every ventilating district, as near as practicable to the point where the air is sub-divided at the end of a split and also where it enters the first working place; and(iv)any other point that the Regional Inspector may, by an order in writing, specify,(b)The measurements referred to in clause (a) shall be entered in a bound paged book kept for the purpose:Provided that in a non-fiery seam or a gassy seam of the first degree it shall be sufficient to take the air measurement once in every thirty days.
