Owners or operators of all continuous monitoring systems installed in accordance with the provisions of NAC 445B.256 to 445B.267, inclusive, shall check the zero and span drift at least once daily in accordance with the method prescribed by the manufacturer of the systems unless the manufacturer recommends adjustments at shorter intervals, in which case the recommendations must be followed. The zero and span must, as a minimum, be adjusted whenever the 24-hour zero drift or 24-hour calibration drift limits of the applicable performance specifications in Appendix B of 40 C.F.R. § 60 are exceeded.
Nev. Admin. Code § 445B.261
NRS 445B.210, 445B.225