Whole Leaf Tobacco

How to Make A Wet Bulb - Dry Bulb Thermometer Set-Up on the CHEAP

AmaxB

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Making a Dry / Wet Bulb Set-Up

Dry Bulb / Wet Bulb thermometers can be used to get the Relative Humidity of an inclosed environment, such as that of a Kiln, Curing Chamber, Shed, etc., and so on. The Dry Bulb / Wet Bulb Thermometers can help to ensure the outcome of your Tobacco by allowing you to monitor the Relative Humidity.


Below I attempt to show you how to make one that I have checked against a PID Relative Humidity Controller and found to be accurate.


What you need to make one:
Two Thermometers
Tube type boot / tennis shoe lace
Solid type tennis shoe lace
Wire Ties – Zip Type
Wire Bread Tie
1/2 Inch Wire Screen
A Glass Bottle w Cap able to stand up to 200F
Water

Most of these items you likely have already just laying around :confused:

For your Thermometers I would recommend 2 of these your cost for them about $14.00 including shipping found them on E-Bay here http://www.ebay.com/itm/120712641637?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649


Step 1
Cut a piece of wire screen large enough to fold all 4 sides twice and still accommodate your bottle and thermometers. I would suggest laying the thermometers and bottle on your screen before cutting to get the size you need keeping in mind you are going to fold the sides over. You want to fold the sides to make the screen more ridged.
While you have your thermometers laying on the screen mark the location of the bulb for the thermometer you plan to use as wet it should be near the bottle opening.


Step 2
Fold all for sides of your screen and attach your bottle without the cap. To attach my bottle I used Aluminum wire. Than cut out a section of screen where the bulb of your Wet Bulb Thermometer will be located. Cut it out large enough so no screen will come in contact with the thermometer bulb or boot lace when it is in place.
You should have something that looks like this.
.
01-Screen Bottle.JPG-02-Hole in screen Wer-Bulb.JPG
.

Step 3
Cut the tube type Boot / Tennis Shoe Lace to 11 inches long and cut the solid type Boot / Tennis Shoe Lace to 12 inches long.


Step 4
Threading the Laces
Attach one end of the Solid Lace to a piece of wire using tape. Bend the other end of the wire so it can't snag and push it through the tubular lace. With a little care using the wire and working the tubular lace pull the solid lace through the tubular one until it is all the way through.
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03-Tread inner Lace-wire.JPG-04-Thread outter 2 inner done.JPG
.

Step 5
Cut the guard section protecting the bulb of the thermometer you plan on using as wet away.
Than pulling the solid lace enough to have it just inside an end of the tubular lace so it can touch the bulb of your wet bulb thermometer. Slip this end of the tubular lace over the bulb of the thermometer you are going to use as wet and fasten with the wire bread tie.
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05-Thermometer Cut Out.JPG
.

Step 6
Attach your thermometers to the wire screen backing using the wire zip ties. The bulb of the thermometer you plan to use as wet should be over the hole you cut in the screen for it. It should not touch the screen nor should the tubular Boot / Tennis Shoe Lace.
.
06-Thermometers attached.JPG-07-Attached looks like this.JPG
.

Step 7
Make a hole in your bottle cap, make it large enough to get the Boot / Tennis Shoe Lace through so it is slightly snug but not tight at all. My bottle cap has a rubber nipple on it yours does not need to be like mine.
.
08-Bottle cap and lace.JPG
.

All done this is what you should look like. Last thing you should have close to 5 inches of Lace between the bottle cap and bulb of the wet bulb thermometer.
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09-finished view.JPG
.
Now fill the Bottle with water, holding the lace screw the cap on. Good luck with your Tobacco
You can use this calculator to get your Relative Humidity by inputting the Dry Bulb Thermometer and We Bulb Thermometer temperatures. http://home.fuse.net/clymer/water/wet.html


 

deluxestogie

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Very nice. As of 4:30 am 8/1/2013, your post appears in the first page of Google search results for "wet bulb tobacco".

Bob
 

AmaxB

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There is one thing I failed to mention, it is important...
Before starting place the Thermometers side by side and check to be sure you have the same reading on both. If not and one is off a bit loosen the glass body of one thermometer and slide it up or down until it matches the other thermometer. Than tighten the fasteners do this carefully so you don't break your thermometer. This is how you calibrate them.
Top Page of Google hey that's pretty good :cool:
It is good to share by doing so we all can grow and succeed with the task at hand.
 

deluxestogie

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If the thermometers differ, you can get a true temp--determine which, if either is correct--by placing the bulb in a container of ice and water (that has rested a bit to reach a stable temp). It should read exactly 32ºF.

Bob
 

gracebowen

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I think I have the most expensive hydrogometer. I got it from my Geology class. It only cost one thousand dollars and its already breaking. lol
 

AmaxB

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New Dry/Wet Bulb design
.
new design 9-17-13_2.jpg

The snap on connector is made to go on an existing water line / when installing you would use cement and drill a hole in the existing line.
Here I drill no hole and do not use cement, I just snapped it on - this allows my mount arm to pivot and move up or down. It is usefull
to position thermometers after they have been mounted to the arm. The arm end I left extended a bit in the event I want to add peices
for support on this side so it can stand on it's own. Also I used no cement on the arm parts so they can be changed if wanted and allowing
for the arm it's self to turn.

The wick is shoe string and in looking at the photo you can see by the Blue line how it is laced through the pipe and into the water reservoir.
It attaches to the Wet Bulb.

Last is the fill cap.

The big reason I wanted the pivot and up/down movement is obvious - (so I can position for best view through my window, placement over
tobacco, and air flow.)

I implemented this design when I started Batch 6 to curing yesterday and it is working well.
 

AmaxB

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Nice to have you back leverhead!!
Yeah man that can work...
This morning I thought I would experiment a bit and took a temperature sensor (K type) from one of my temperature controllers that I am using to monitor temperature (it controls nothing) and slipped it into the shoe lace for my wet bulb and they are pretty close in readings. I think the digital is more accurate it is about 3 degrees higher than the glass thermometer.
 

leverhead

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Nice to have you back leverhead!!
Yeah man that can work...
This morning I thought I would experiment a bit and took a temperature sensor (K type) from one of my temperature controllers that I am using to monitor temperature (it controls nothing) and slipped it into the shoe lace for my wet bulb and they are pretty close in readings. I think the digital is more accurate it is about 3 degrees higher than the glass thermometer.
My post #13 does not work so well the wick drys out.......:(
It's good to be back! I haven't calibrated any of my stuff, three degrees isn't that much of a difference and neither one is more likely to be right. I'm kilning now, I've got one RANCO controlling the power to the two crock pots and the other RANCO controlling the big blower to move some air out the vent. The second RANCO is set up as a wet bulb with a cooling function, as the wet bulb goes above the set point it turns the blower on to vent some air out and bring the RH down.

I try not to make the wick lift water more than a couple of inches. For flue-curing, even that can be too much. Flue-curing puts allot of crud into the air inside the box that puts a crust on the wick. A long or wide or both, but shallow water container would have more water available for less reduction in height as it gets used up.
 

Brown Thumb

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I read somewhere to change the wick after every batch, That is large scale tho, Does it matter, Small scale?
WTF do I Know.
 
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