PBTs shall be checked for accuracy by a BAT or an individual specially trained to perform PBT accuracy checks at least once every 93 days. To be accurate, the PBT must quantitate a reference sample within 10 percent of the reference sample's value, as adjusted for environmental factors.
Ill. Admin. Code tit. 20, § 1286.250
Amended at 35 Ill. Reg. 18897, effective October 31, 2011