A gas sensor usable in harsh environments includes a multiple chamber radiant energy transmission path which extends between a multi-channel emitter and a multi-channel detector. Furthermore, a method of brake fluid disposal is characterized in that the recovered glycol-based brake fluid is mixed with diethylene glycol. The power amplifier amplifies an RF signal for transmission with an adjustable gain. During a second interval the semiconductor plate and another electrode produce an RF electromagnetic field that results in a plasma that etches electric layers, underlayers and photoresist layers from the wafer.