Quoting Marc Nicholas : Seems to me that you really should start with a specification (or some idea of what you require) and go from there. I have used thermocouples (open wire wire and open ribbon) for really fast response with air (for example, to control a proportional valve for a = combustion heated air flow). But to get 0.1=B0C *accuracy* is probably optimistic unle= ss it's laboratory conditions. 0.1=B0C short term stability shouldn't be a pro= blem with good instrumentation and controls. > I'm doing a lot of work with thermistors these days....my current prototy= pe > is <0.1c accuracy and 0.1c resolution on the digital side. This is from a= $4 > thermistor encased in copper. > > You'll actually find "standing air" response times published by most > thermistor manufacturers -- as long as it's a thermistor truly meant for > instrumentation. In my experience, they're in the order of 25s in standing > air. Moving air, stirred oil, and water figures are sometimes supplied and > will all be faster. > > Not sure if that really helps, my my 2 cents Canadian ;) > > -marc > > On Wed, Jun 25, 2008 at 12:13 AM, PicDude wrote: > >> >> I'm searching for a fast temp sensor for measuring ambient air temperatu= re >> (with some overhead) -- say -10deg-C to 120deg-C. 1% accuracy or better. >> >> There are a lot of sensors that meet this numerical criteria, but what >> types >> of temps sensors are *fast*? I usually don't see response time listed in >> the datasheets (and not even sure what the parameter is for response tim= e), >> and I don't have a specific value for how fast it should be, but I want = to >> compare various sensor types and start investigating/experimenting with = the >> fastest of these. >> >> I did find "fast response RTD's" and wondering how they compare >> (speed-wise) >> to other alternatives such as semiconductor sensors. I expect the plast= ic >> housings for TO-92 types and similar would be enough of an insulator to >> significantly increase the response time. Will the metal can versions >> (TO-39 IIRC) be considerably faster? Open element sensors and low-mass >> sensors should be fast. But I'm sure I am missing a lot of other >> possibilities here. >> >> Any links/clues on this? >> >> Thanks, >> -Neil. >> >> -- >> View this message in context: >> http://www.nabble.com/Fast-temp-sensor--tp18104658p18104658.html >> Sent from the PIC - [EE] mailing list archive at Nabble.com. >> >> -- >> http://www.piclist.com PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> > -- > http://www.piclist.com PIC/SX FAQ & list archive > View/change your membership options at > http://mailman.mit.edu/mailman/listinfo/piclist > Best regards, Spehro Pefhany -- = "it's the network..." "The Journey is the reward" s...@interlog.com Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com -- = http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist