(a) The mine atmosphere shall be tested for methane and carbon monoxide at least once every seven days by a competent person or an atmospheric monitoring system, or a combination of the two. Such testing shall be done at the following locations:
(b) The volume of air (velocity in Subcategory I-A mines) shall be measured at least once every seven days by a competent person. Such measurement shall be done at the following locations:
(c) Where such examinations disclose hazardous conditions, affected persons shall be informed and corrective action shall be taken.
(d) Certification of examinations shall be made by signature and date. Certifications shall be retained for at least one year and made available to authorized representatives of the Secretary and the State Mine Inspector.
053-3 Wyo. Code R. § 57.22229
52 FR, 24941, 7/1/1987, as amended at 52 FR 41397, 10/27/1987