Model SA-XES gas detection systems use an extractive sampling pump to deliver an air and gas sample to one or more gas sensors in sample flow cells mounted in the system enclosure. Gas type and detection range are determined by installing selected Safeguard Analytics Model SA1 smart sensor modules. System capacity can be specified for 1 to 4 dual sensor modules creating up to 8 different active gas sensors. Smart sensor options include combustible gases, toxic gases, oxygen deficiency and volatile organic compounds. The system is modular and features a color graphic display that serves as a MODBUS master, internally mounted sensor flow cells, a “Smart Pump” assembly and an integration connector board for connecting external meteorological devices. System output is MODBUS RTU 9600 bps. Smart sensor modules can be pre-calibrated using a portable calibration kit or calibrated in situ using demand flow regulators and applicable span gas sources. The system is packaged in a NEMA 4X weatherproof enclosure suitable for installation in outdoor non-hazardous locations. Power options are 10-30 VDC or 90-240 VAC.