Kegconnection Complete Starter Kit and More Giveaway!


Home Brew Forums > Home Brewing Beer > Automated Brewing Forum > WaterWeld DS18B20 temperature sensor to side of keggle

Reply
 
LinkBack Thread Tools
Old 05-13-2013, 01:10 AM   #1
brant740
Feedback Score: 0 reviews
Recipes 
 
Join Date: Oct 2012
Posts: 110
Liked 4 Times on 4 Posts

Default WaterWeld DS18B20 temperature sensor to side of keggle

Has anyone attached a ds18b20 directly to the side of a kettle or keggle? I am not talking about using a well or compression fittings or drilling any new holes. I was thinking of using a DS18B20 sensor with thermal grease and a tab of JB waterweld to hold the sensor tight to the kettle. Would the kettle metal temperature be a fair representation of the water temp?

__________________
brant740 is offline
 
Reply With Quote Quick reply to this message
Old 05-13-2013, 03:36 PM   #2
crane
Feedback Score: 0 reviews
Recipes 
 
Join Date: Sep 2011
Location: San Diego, CA
Posts: 280
Liked 25 Times on 22 Posts
Likes Given: 1

Default

I don't think this will e a very accurate way to measure temperature, nor would it be a robust solution. I assuming you would solder wire to each leg of the sensor and cover it with heat shrink. The legs on electrical components are not meant to put up with much stress. The weight if the cable would break the legs quicker than you would expect.

Measuring the outside surface of the kettle is not going to be the same as measuring the inside surface. It's going to come down to the equation where the temp difference between inside and outside surfaces are equal to the thermal resistance of the material multiplied by the amount of heat being transferred through the kettle wall. There will always be heat transfer when you have a heated liquid inside the pot therefore there will a delta across the kettle wall. You may be able to compensate for this but you still need to deal with the robustness problem first.

I do like the idea you are presenting but I think to make it work well will require a bit more effort than you describe to make it robust and therefore you may end up with something more involved and complicated than simply drilling a hole for a thermal well.

__________________
crane is offline
 
Reply With Quote Quick reply to this message
Old 05-13-2013, 04:04 PM   #3
brant740
Feedback Score: 0 reviews
Recipes 
 
Join Date: Oct 2012
Posts: 110
Liked 4 Times on 4 Posts

Default

Thank you for the insight. I think I can get around the fragile legs by tacking the head of the sensor, heat shrinked legs and the wire with water weld epoxy. This should immobilize the sensor and transfer stress point to where the wire is attached.

My admittedly noon question is how does a ss well differ from a ss kettle on detecting temps? Should heat transfer be similar?

__________________
brant740 is offline
 
Reply With Quote Quick reply to this message
Old 05-13-2013, 07:14 PM   #4
crane
Feedback Score: 0 reviews
Recipes 
 
Join Date: Sep 2011
Location: San Diego, CA
Posts: 280
Liked 25 Times on 22 Posts
Likes Given: 1

Default

The thermal well is submerged with water in all directions except where it contacts the kettle but usually this is far enough away from the sensor that you can consider the thermal well to be completely surrounded by water. Therefore the tip of the well where the sensor is will be very close if not the same temp as the water. Once in equilibrium there will be no thermal transferred through the thermal well or temp sensor, whereas there will always be heat transferred through the kettle wall.

At my last company I worked on a problem where we were trying to roughly measure the temperature of water or steam inside of a pipe by measuring the outside surface of the pipe. We were able to come up with a solution that worked half ass when there was no airflow, but as soon as you added the slightest airflow the delta between inside pipe temps and surface temps changed by a lot. The surface temp of kettle will vary depending on air temperature and wind speed.

__________________
crane is offline
 
Reply With Quote Quick reply to this message
Old 05-14-2013, 02:59 PM   #5
Indian_villager
Feedback Score: 0 reviews
Recipes 
 
Join Date: Apr 2010
Location: Claymont, Delaware
Posts: 392
Liked 30 Times on 23 Posts
Likes Given: 6

Default

These are cheap.
http://www.brewershardware.com/Straight-Tubes/

__________________
Indian_villager is offline
 
Reply With Quote Quick reply to this message
Old 05-14-2013, 07:27 PM   #6
brant740
Feedback Score: 0 reviews
Recipes 
 
Join Date: Oct 2012
Posts: 110
Liked 4 Times on 4 Posts

Default

That makes sense. I suppose I will have to bite the bullet and go with a well. I do have premade stainless probes, but I wanted to limit the number of holes in my kettle.

__________________
brant740 is offline
 
Reply With Quote Quick reply to this message
Old 05-15-2013, 05:55 AM   #7
helibrewer
HBT_SUPPORTER.png
Feedback Score: 1 reviews
 
helibrewer's Avatar
Recipes 
 
Join Date: Nov 2011
Location: Santa Rosa, CA
Posts: 3,073
Liked 173 Times on 157 Posts
Likes Given: 39

Default

Quote:
Originally Posted by brant740 View Post
That makes sense. I suppose I will have to bite the bullet and go with a well. I do have premade stainless probes, but I wanted to limit the number of holes in my kettle.
I fill my thermowells with mineral oil (cutting board oil) which really improves heat transfer within the well.
__________________
Something is always fermenting....
"It's Bahl Hornin'"

Primary:
Brite Tank/Lagering:
Kegged: Hefeweizen, Chocolate Hazelnut Porter, Kumquat Saison, Tart Cherry Cider, Belgian Tripel, Maibock Bock, Ommegang Abbey Ale Clone, Belgian Golden Strong, German Pils (WLP830)
Bottled: Belgian Quad (Grand Reserve), Derangement (Belgian Dark Strong)
On Deck:
My Site: www.restlesscellars.com
helibrewer is offline
 
Reply With Quote Quick reply to this message
Old 05-15-2013, 01:32 PM   #8
alien
Feedback Score: 1 reviews
Recipes 
 
Join Date: Apr 2012
Location: Philadelphia, PA
Posts: 1,233
Liked 64 Times on 58 Posts
Likes Given: 61

Default

Stainless is not a terribly good conductor of heat as metals go so where you put the probe matters. Plus you need to insulate. I would recommend a small, flat thermistor which will give you a better contact than a DS18B20.

http://www.rapidonline.com/electroni...mistors-61185/

__________________
Magic Smoke brewhouse and grill

Arduino PID controller - Automatic Smoker - Cooler MLT - Counterflow Chiller - SSR demo - PWM timer - Folding Brew Table
alien is offline
 
Reply With Quote Quick reply to this message
Reply


Quick Reply
Message:
Options
Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Mounting of DS18B20 in Keggle waldzinator Automated Brewing Forum 14 04-19-2013 04:29 PM
1-Wire DS18B20 Waterproof Temp Sensor thermowell? Homercidal DIY Projects 1 01-17-2012 03:22 PM
PID and I2C Temperature Sensor? TriangleIL Electric Brewing 17 02-22-2011 08:49 PM
temperature sensor to 10 bit ADC cheese Electric Brewing 10 12-14-2010 06:55 PM
Temperature sensor for DAQ board cheese DIY Projects 4 10-28-2010 06:09 AM