Zeman, I would use a chromel/alumel thermocouple, as they are pretty bulletproof and can easily go to much higher temperatures than 400C. The biggest problem with them is that they only measure the difference in temperature between the hot end and the cold end. If you need more accuracy than this allows, then you need an ambient temperature sensor for compensation (LM35 etc.?). The other "problem" with thermocouples is their low sensitivity but 100 to 400 C range shouldn't be too hard-- 75C delta T gives (room temp ~25C so 100C -25 = 75C) about 3mV and 375C delta T gives about 15mV. As you can see, it is pretty linear (at about .04mV/deg C) -- Looking forward: Alan Shinn Experience the beginnings of microscopy. Make your own replica of one of Antony van Leeuwenhoek's microscopes. visit http://www.mindspring.com/~alshinn/ Date: Thu, 6 Dec 2001 23:37:47 -0400 From: Zemin Liu Subject: [EE]: High temperature sensor >Hi all, > >I am trying to make a temperature controlled heat gun myself. Does anyone >have experience on making a homebrew high temperature (100 - 400 degree C) >sensor? Any suggestion is welcome. >Thank you in advance! >Zemin -- http://www.piclist.com hint: To leave the PICList mailto:piclist-unsubscribe-request@mitvma.mit.edu