On 28/10/2010 13:34, Olin Lathrop wrote: > Apply the same voltage to all during production test and store calibratio= n > values in EEPROM. > > Nice, but what would be more ideal is the following: a) ADC and its attenuator (say 1% tol.) are calibrated once against a=20 precision external source b) Multi HV unit can then self-calibrate each channel, as the attenuator=20 is switched between HV outputs. Thanks also to everyone else for all the interest so far... Matt --=20 http://www.piclist.com PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .