John, > Temperature... Corrosion... Gremlins... Temperature may be a degree. Others rules out. > Figuring out how to measure at least one of > > the above will further your venture, my guess. Bob suggested to look at the caps. Cheers Ravi > > On 9/9/14, Ravi wrote: >> Hi Guys, >> >> I have a 555 based oscillator, AC couple and the probes are in salt >> water of a given concentration. >> >> The probes are in water for about 1 hour from 8 PM to 9 PM and the >> reading is 6500 Hz. I switch off the unit. >> >> The next day at 9 AM in the morning I see that the value has changed to >> 7000 Hz. >> >> What could be causing the drift? >> >> Cheers >> >> Ravi >> -- >> http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive >> View/change your membership options at >> http://mailman.mit.edu/mailman/listinfo/piclist >> --=20 http://www.piclist.com/techref/piclist PIC/SX FAQ & list archive View/change your membership options at http://mailman.mit.edu/mailman/listinfo/piclist .