Auto and manuall tuning a PID

[BeerCat]

I am really pleased seems to be working now. I mashed in around 5c under what i wanted then ran autotune. Seems to be holding within 0.1c either way now. Next step is to make sure the probes are calibrated correctly. As Fil said cheap stuff. I have a 300mm SS one that measures 10c out as is going rusty. I will post my settings later in case anyone is interested.

 

[Bigcol49]

I am really pleased seems to be working now.

Hi!
That's good news. :thumb:

 

[eyuptm]

Gawd, there are some brains on here!! Seriously good thread, and it's good to have a peep into someone else's specialisms, even just to realise just how much more there is to know!! Now to rest my overheating brain for a while- can anyone suggest a cooling aid???!!!

 

[johncrobinson]

I trained as an intrument and control engineer about 45 yrs ago,The principles of pid are simple,The maths are NOT.
Most auto pid will tune to +/- 1 degree or better.
I think you may have other problems.First guess would be thermal connection between the process and sensor or sensor problems.Keep the sensor in close contact with beer/wort and insulate fron outside enviroment(you do not want to measure ambient temp) is probe in beer is best.NOT on outside of plastic keg for example.(this causes time lag !!)