Paragraph 7
Determinations of the firedamp content shall be made at every point required by or under the two last preceding regulations once in every week:
Provided that—
if any determination at any such point shows a firedamp content exceeding 0·8 per cent. by volume determinations shall be made at the corresponding point at intervals not exceeding twenty-four hours so long as the content is shown to exceed or to have exceeded that percentage and for the seven next following working days, unless an inspector by notice served on the manager otherwise consents;
if every determination made during a period of thirty days at any such point showed a firedamp content not exceeding 0·6 per cent. by volume it shall be sufficient to make determinations at the corresponding point at intervals not exceeding thirty days for so long as the firedamp content shown thereby does not exceed that percentage.
Notwithstanding anything in the last preceding paragraph whenever any alteration is made in the arrangements for ventilating a mine which affects or may affect substantially any part of the mine in which determinations of the firedamp content have to be made, a determination of the firedamp content at each point in that part shall be made as soon as any substantial effect of the alteration would be apparent.
Any determination of the firedamp content shall be made, if the relevant face is machine-cut, during the latter part of the cutting shift or, if the face is not machine-cut, during the latter part of the filling shift:
Provided that if it appears to the manager or an inspector, as the case may be, that the firedamp content is normally greatest at any point at any other stage of the operations, determinations at that point may be made at that stage if an inspector by notice served on the manager consents thereto and shall be made at that stage if an inspector by such notice so requires.
The provisions of Part XV of the Act with respect to references upon notices served by inspectors shall apply to a notice of requirement under the last preceding paragraph and either of the following shall be a relevant ground of objection to such a notice, namely—
that the firedamp content at the point in question is not normally greatest at the stage referred to in the notice;
that the greater firedamp content at that stage at that point is transitory.
Where determinations of firedamp content are made once in every week or thirty days they shall as far as practicable be made at the appropriate stage of the operations on the last working day of the week, other than a Saturday, on which the operations comprise that stage.