What’s inside a Dräger Multiwarn II gas detection warning system used in mining, oil, chemical, and emergency services etc to detect hazardous or explosive atmospheres.
Intrinsic safety design and how both catalytic bead and infrared IR gas detectors work, and pellistors.
And a teardown of a Hydrogen Sulfide (H2S) sensor.
http://www.a11supply.com/images/file/rev1_MultiWarn%20II_En.pdf
http://www.draeger.com/sites/assets/PublishingImages/Products/cin_x-am_5600/US/draeger-sensor-portable-handbook-9046571.pdf
http://www.xinpian.net/MOTOROLA/MC68HC711/MC68HC11E1.pdf
Forum HERE
Podcast: Download