Need everyones help on a PID problem

Wildcat · February 07, 2008, 06:07:23 PM

Will do Sparky

Mr Walleye · February 07, 2008, 06:12:37 PM

WildCat

Are you checking your temps with your ET73?

Mike

Wildcat · February 07, 2008, 06:20:01 PM

Only so that I know my true box temp and meat temp. The information on what I have been referring to are from the PID only. I am trying to maintain a box temp of 205 on my ET73, which at the moment requires a setting of 214 on the PID.

Also, my temp swings went to +/- 5 degrees from the 214 setting, so I am currently running another auto tune.

Wildcat · February 07, 2008, 07:00:17 PM

Auto tunes have only been taking about 25 minutes. After this latest, temps swung -4 to +3 around the 214 set up. After a few minutes it stablized at 214 to 215 box temp with it set at 214. After about another 15 minutes it went down to 212 and slowly went back to the 214 to 215. Will continue to monitor.

Arcs_n_Sparks · February 07, 2008, 07:03:02 PM

Quote from: Wildcat on February 07, 2008, 07:00:17 PM
Will continue to monitor.

All this monitoring is making me thirsty...

I am starting to drink, at a distance. :D :D :D

Wildcat · February 07, 2008, 07:05:18 PM

Yea. I think I will make myself a crown and sprite and join ya.

Mr Walleye · February 07, 2008, 07:11:08 PM

WildCat

I'm just trying to get my brain around your numbers.

The PID set temp is 214. Currently at 214 to 215.

ET73 is reading 205.

I'm wondering where your thermocouplers are for both the PID and the ET73?

Mike

Wildcat · February 07, 2008, 07:28:13 PM

PID set for 215. PID now reflecting box temp between 213 and 215. Fluctuation is less now. May change again later. We shall see. The ET-73 fluctuates along with the PID readings, but at temps of 199 to 203 now. Both are right next to each other. They are simply hanging above the meat without touching. Not my favorite place to put them, but it is the only location where the loooong PID probe will not touch metal. That is why I am cooking at 200 to 205 ET-73 box temp. I figure the bottom of the meat is around 207 to 210.

Wildcat · February 07, 2008, 07:48:50 PM

Quote from: Arcs_n_Sparks on February 07, 2008, 06:02:51 PM
Wildcat,

Let me know what your final PID numbers are, and I will post with the rest.

Arcs_n_Sparks

Sparky - Since I seem to be back at the +/- 1 degree, I do not think I will auto tune anymore tonight. My numbers are P=498 I=191 and D=172.

I do not think much of this particular PID probe (thermocouple). Will probably get a different one and see what I have at that point.

Mr Walleye · February 07, 2008, 07:49:30 PM

I wonder if you try changing the offset again to -12 and give it 15 minutes or so and see what all your temp readings are.

Maybe before you try this you should record your current P, I & D settings just in case. That way you can always manualy change them back if it doesn't work.

Mike

Wildcat · February 07, 2008, 07:52:34 PM

OK - I'll give it a try now. One question - Do I need to auto tune after I do this?

Mr Walleye · February 07, 2008, 07:55:28 PM

No, you shouldn't have to. It's just adjusting the display numbers to my knowledge.

Mike

Wildcat · February 07, 2008, 08:05:34 PM

;D ;D ;D I went and did the change. I realized what I did wrong last time I tried to do this. I had set it at -1.2 vice -12.0. Duh! Now they should read the same. I will fine tune that setting after awhile. Still do not like this PID probe. It is so long that I have no place to put it other that hanging above the meat. If I go below the meat, it hits the V tray. The meat is on the second position from the top. If the PID continues to read the same as the ET-73 then I will probably move the ET-73 to just under the meat and off to the side so that I can get a good reading.

Thanks again for your help.

Mr Walleye · February 07, 2008, 08:15:27 PM

No problem WildCat.

Let me know what everything reads in a few minutes. I'm really curious now.

I will have to take a picture of the bracket I built for my PID TC. I have it coming down through the vent, over to the top rear corner, down the corner to about midway down the tower, then I built and attached a bracket that the TC snaps into and it keeps it off the back wall. It's not the ideal place because it is usually a little warmer at the back of the cabinet but this way I don't have to ever move it.

Mike

Wildcat · February 07, 2008, 08:23:08 PM

Sounds interesting. I have learned that it (the metal part) can not touch other metal. I e-mailed Pat and he said that he just uses a wire thermocopule (no metal probe, and simply wraps it around one of the racks to hold it in place.

The butt was in for 4 hours about 15 minutes ago. I changed the water bowl and spritzed the butt with some apple juice, so it will be a little bit getting back up with the ET-73. Just before that I changed the setting on the Pb a couple of degrees and matched the ET-73. We will see how it goes after a few more minutes.