thanks for the responses...i've forwarded these sites to my client for his = review. When you said you have had better luck with RTD's over thermocoupl= es, can you explain what your experiences were? RTD's are generally less e= xpensive, but are they as stable as a thermocouple? =20 --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .