Dear Steve:

I want to control Temperature of an about 10 liter chamber, I have also a convection fan to speed up the equilibrium. user places high thermal capacity material in the chamber. thermal isolation is not very good(but there are some thermal isolations), that's because to allow the chamber to cool down to room temperature(over heating should be avoided). the max temp is about 45 degree centigrade and a few minutes time to reach equilibrium is acceptable.
I was thinking to use a relatively low power heater(maybe 100W). if the power of heater is relatively low, there is no chance for quick temp change and in that way a 1 Hz or even 2 Hz sampling rate should be enough. lower sampling rates, means more free time for MCU( the mcu has other jobs too, like processing 16 bit & 10 bit A2D inputs, because of 16 bit A2D I've decided to use half wave 220V AC for heater to lower EMI).


thank you very much