Introducing the ALTAIR 2X gas detector from MSA, the first one or two gas detector that incorporates industry-leading XCell Sensor Technology to deliver unparalleled performance while drastically minimizing total cost of ownership, increasing durability and delivering enhanced worker safety, compliance and traceability. The Altair 2X is also the first portable gas detector to introduce revolutionary XCell Pulse Technology. Based on proven science and advanced patented sensor capabilities, the Altair 2XP detector delivers the world's first stand-alone bump test. This allows a daily bump test to be performed without the need for calibration accessories or specific calibration gas. The Altair 2XP gas detector provides a bump test that is so easy to follow, anyone can do it, from anywhere! The science behind this first-of-its-kind technology will change the face of portable gas detection as we know it. By combining pulse sensor interrogation with a simple flow check, we've created the first successful stand-alone bump test. PULSE sensor interrogation begins, exhale into the unit.