PID Controller with Ramp/Soak option?

[foomench]

A while back I bought two PID controllers for automating my brewery. I'm kind of coming to the conclusion that I don't want to use these type K thermocouple controllers and instead want to get something compatible with RTD sensors. So I was browsing at Auberins and I saw the PID Temperature Controller w/ Ramp/Soak. Is anyone using one of these, or tried to? It seems it could be programmed to do a protein rest, ramp up to saccharification temperatures, hold, then ramp up to mash out. Even when not doing a protein rest, programming in the time and ramp for mash-out would be pretty handy. If this is easy to program and works reliably, it might be worth the extra $45. What do you think?

[ajdelange]

For the narrow range of brewing temperatures I think RTD's are much better than thermocouples. They are more immune to noise, can be hooked up with copper wire, you don't need to worry about reference junction temperature and so on.

PID control is great - once you get it tuned. Improperly tuned, it will take you forever to get to the SP temperature or you will overshoot. You will probably find that you need a differernt tuneset for different levels of grain in the tun and different water to grist ratios. Getting the tuning coefficients without wasteing grain can be a bit of a challenge.

A real problemn with the use of controllers in brewing IMO is being sure that the mash is of uniform temperature i.e. uniformly mixed. If that's not the case then a good controller is not going to be of much use. It is because of this that I don't use PID controllers in my system except on the HLT which is easily kept well mixed by recirculation (and where PID control is hardly needed).

[roc-craven]

I use the Auberins controllers. They work very well. I started with j-type TC now I have RTD's. there is a marked difference in the accuracy with the RTD's. The PID's are really easy to use and the have good customer service if there is a question. But they can be hard to understand with their accents, but they are good anyhow. There are some pics of my PID's here. http://www.beerbelliesbrew.com/HERMSController.html The controller box looks differnt now but still have the same controllers.

My 2 cents worth.