30 CFR § 75.1103-3
Automatic fire sensor and warning device systems; minimum requirements; general.
Automatic fire sensor and warning device systems installed in belt
haulageways of underground coal mines shall be assembled from components
which meet the minimum requirements set forth in §§75.1103-4
through 75.1103-7 unless otherwise approved by the
[37 FR 16545, Aug. 16, 1972]