OK, here's another problem I've been playing with (although it has little to do with IPC mission, it might be related). I am trying to build a system for measuring airborne particulates for humanitarian organizations looking for inexpensive ways to measure/monitor indoor air quality. There are cheap sensors available which might do the job, but they would need periodic re-calibration. So I need a controlled, extremely small amount of smoke. At first, I thought this would be trivial: Find a cheap part at DigiKey and put too many watts through it. Way too much smoke and too little control. Then I tried burning thin wires. Too irregular because sometimes they incinerate completely and other times they find a tiny defect and just burn that until the wire stops conducting. Then I tried just heating the wire enough to burn off the insulation. Still too irregular! I did just a few experiments and got 30% variation. Now I'm starting to think maybe a tiny piece of paper on an automotive cigarette lighter. That's a lot of power to get that glowing, and it is not convenient to attach to. Any other ideas? Wayne ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________