Temp sensor fluctuation - Page 2 - Home Brew Forums
Home Brew Forums > Home Brewing Beer > Electric Brewing > Temp sensor fluctuation

Reply
 
Thread Tools
Old 03-11-2011, 07:43 PM   #11
Boerderij_Kabouter
 
Boerderij_Kabouter's Avatar
Recipes 
 
Dec 2007
Oconomowoc, Wisconsin
Posts: 7,750
Liked 147 Times on 119 Posts


Layne, are all the sensors acting the same? Or is one different from another?



 
Reply With Quote
Old 03-11-2011, 07:48 PM   #12
Layne
HBT_SUPPORTER.png
Recipes 
 
Sep 2008
Gonzales, Louisiana
Posts: 964
Liked 19 Times on 17 Posts


They all fluctuate constantly.
I have not compared them to see if it is a similar amount, or the same time/pace, but I do know that on two different nights, I tried to calibrate. One night on the phone woth you BK, and last night. And those were NOT the same sensor, but had similar results.
I don't remember how much range the first time, but last night, it was 7 degrees.



 
Reply With Quote
Old 03-11-2011, 10:09 PM   #13
Boerderij_Kabouter
 
Boerderij_Kabouter's Avatar
Recipes 
 
Dec 2007
Oconomowoc, Wisconsin
Posts: 7,750
Liked 147 Times on 119 Posts


This is the cable that runs from the sensors in the main box to the remote box:

http://www.l-com.com/item.aspx?id=5882

I am of the understanding that the fully shielded nature should protect the sensors from noise???

I did run the sensors past some 220VAC wires in the main box (unshielded) but i didn't think that would make a big enough difference...

In this pic, you can see where the AC runs (orange wires, the other hot leg isn't installed in that pic, but takes the same route) and where the sensor wires enter (the four white cables).


Here you can see how they are next to each other for about 4 inches in the conduit.


I have had a lot more AC/sensor interaction than this with no noise issues before, but maybe the BCS is very sensitive to noise. I need to figure this out.

I am really sorry about this headache Layne. When I fired it up, the sensors read evenly but were just about 1-1.5 degrees off from one another. Have you tried re-entering the factory coefficients???

 
Reply With Quote
Old 03-11-2011, 10:31 PM   #14
Boerderij_Kabouter
 
Boerderij_Kabouter's Avatar
Recipes 
 
Dec 2007
Oconomowoc, Wisconsin
Posts: 7,750
Liked 147 Times on 119 Posts


Layne, are you operating any of the other outlets during the calibrations or readings?

Additional info, the shielding is grounded.

 
Reply With Quote
Old 03-11-2011, 10:40 PM   #15
Layne
HBT_SUPPORTER.png
Recipes 
 
Sep 2008
Gonzales, Louisiana
Posts: 964
Liked 19 Times on 17 Posts


Nothing else is on.
I just put in Derrins coefficients and it's WAY better.

 
Reply With Quote
Old 03-12-2011, 12:01 AM   #16
Layne
HBT_SUPPORTER.png
Recipes 
 
Sep 2008
Gonzales, Louisiana
Posts: 964
Liked 19 Times on 17 Posts


They are still off, but at least now I believe I can adjust them, now that they are staying constant.
I am brewing right now. I'm using my hand held temp gauge.

 
Reply With Quote
Old 03-12-2011, 02:03 AM   #17
kladue
Senior Member
HBT_LIFETIMESUPPORTER.png
Recipes 
 
Dec 2006
Turner, Oregon, Oregon most of the time now
Posts: 2,305
Liked 53 Times on 47 Posts


A couple questions, is the BCS powered by a wall wart power supply?, and are you a ways from town or a power substation. The condition shown on the screen and what you describe are symptoms of poor voltage regulation, as the thermistor circuits are quite sensitive to voltage fluctuations. If the service voltage is fluctuating and the power supply is not regulating very well, the thermistor readings will be bouncing around like shown on the screen shot.

 
Reply With Quote
Old 03-12-2011, 03:08 AM   #18
Layne
HBT_SUPPORTER.png
Recipes 
 
Sep 2008
Gonzales, Louisiana
Posts: 964
Liked 19 Times on 17 Posts


This is good. A tenth here and there is MUCH better than 7 degrees!
All the temps are off from my hand held thermometer, but at least they are consistant.
Tomorrow I will try to fine tune it.
Thanks a million guys.

 
Reply With Quote
Old 03-12-2011, 03:51 AM   #19
Boerderij_Kabouter
 
Boerderij_Kabouter's Avatar
Recipes 
 
Dec 2007
Oconomowoc, Wisconsin
Posts: 7,750
Liked 147 Times on 119 Posts


How sure are you that the hand-held digital is correct? I would check that too...

 
Reply With Quote
Old 03-12-2011, 04:01 AM   #20
samc
Recipes 
 
Aug 2008
Portland OR
Posts: 5,387
Liked 62 Times on 58 Posts


The coefficients provided with the Brewers Hardware probes are ok, but far from perfect. Could be the nature of the beast, but I found that the original BCS probes were more accurate with the provided coefficients.



 
Reply With Quote
Reply
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Quick disconnect temperature sensor for BCS460 wardenwheat Electric Brewing 13 06-27-2012 04:07 AM
BCS temp probe bullywee Electric Brewing 2 02-23-2011 03:34 PM
PID and I2C Temperature Sensor? TriangleIL Electric Brewing 17 02-22-2011 09:49 PM
Electric HLT temp. controller Steven9026 Electric Brewing 5 02-04-2011 12:11 PM
temperature sensor to 10 bit ADC cheese Electric Brewing 10 12-14-2010 07:55 PM


Forum Jump