May I suggest thermistors and other temperature sensors made by Omega? <http://www.omega.com/pptst/44000_THERMIS_ELEMENTS.html> Their range of products is really large and prices are not too bad: <http://www.omega.com/temperature/tsc.html> take a look also to their literature: <http://www.omega.com/techref/> _ Elio Corbolante.