Designed to meet with the toughest industrial requirements, the SMART S-MS allow monitoring flammable contents in harsh environments. They offer an 8 digits back-lit display and 5 mode status LEDs for the gas concentration reading. They feature non intrusive calibration for an accurate and easy adjustment either via Hall-effect switches or IrDA interface and keypad, without opening the instrument and declassifying the area. SMART S-MS is a unique series of gas detectors with a capability of fitting two sensors inside a single sensor head. This gives the possibility to have two independent sensor output that can be confronted. The detectors are rated to SIL3 SW and SIL2 HW.