Carbon dioxide sensing-a mechatronic approach

It is demonstrated that by combining simple mechatronic systems with simple chemical reagents it is possible to design and construct low-cost carbon dioxide (CO/sub 2/) measurement systems potentially suitable for commercial application. In this paper carbon dioxide sensing techniques are briefly reviewed and their limitations noted. An alternative miniature wet chemical analyser technique is proposed incorporating a safe and simple chemical indicator with low-cost optical sensing and mechatronic control to yield smart sensing systems for CO/sub 2/ detection. The construction of a first prototype using various configuration of reaction chamber (volume/spl sim/2.5 mL), a Motorola MC68HCII microcontroller, and precipitate detection by IR LEDs is reported. The prototype is capable of useful measurement in the range of 10 to 100% CO/sub 2/. Current work to extend the range to 1% and 0.1% is also mentioned.