Rel-Tek Corporation (USA) ToxiBoss toxic gas sensor has been approved I.S. to UL913 for Class I, Div 1&2, Group B, C and D hazards (includes H2.) Unlike XP designs, I.S. opens doors to fast installation (unsealed wiring) and ease of maintenance (service in place). Pick a sensing head â CO, O2, H2S, SO2, NO, NO2, Cl2, etc. Supply 1030VDC; 420ma signal; 3wire hookup; 50ma drain. Matching I.S. barriers are available. Used with RelTekâs MagiKal automatic calibration it offers high precision and lowest cost of ownership. ToxiBoss can be ordered with NEMA4x outdoor housing or smokealarm style for indoors. SCADA systems and alarm controllers are available.