Continuous Gas Detection System 1 : A gas detection system in which the instrument is maintained in continuous operation and the interval between sampling of any point does not exceed 30 minutes
NFPA 1 Fire Code, National Fire Protection Association (NFPA), MA, USA 2009 ed. https://law.resource.org/pub/us/code/ibr/nfpa.1.20 03.pdf, (Code: Nat Fire Protection Association Fr&LfSf Requir - Amer) {171 NFC}