How to Turn a Cheap Digital Air Thermo Into a Water Thermo

bendog420

New Member
hi,well after looking at the prices of a digital water thermo and water chillers me and fpf may have come up with a cheaper and more durable solution,at the time the water chiller project is being tinkerd with,but this thread will cover the home made thermo probe you will use later on.

here is what i used and tools you will need--

phillips screwdriver

soldiering iron

soldier

1 - Acu-Rite Digital Window Thermometer(pick it up at k-mart)
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length of wire at least 2 ft (depends on how far you need to reach)

aquarium sealant

caulk gun

piece of air tubing (ill explain length in the thread)

electrical tape

volt multimeter
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step 1-(i started taking pics a lil late so bear with me)ill be hapy to answer any questions)
take the thermometer ,
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,and take the 2 screws out of the top,take off the top(cap) and pull out the thermo part,(ok when you pull the thermo out that little blue thing will be soldiered to the bored where the 2 white wires are coming out of in the pic below,~~((caution))~~ after plugging your iron in let it sit and get to full temp before you try heating up the soldier to loosen the piece from the bored because if you hold it on to long TOO MUCH heat will fry the piece,if needed have someone GENTLY pull on the peice as the soldier pools(melts) it should come loose easily and if your lucky the holes might close up with the excess soldier meaning it will be a bit easier to soldier you length of wire back in
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step 2--making the probe case
ok this step needs started the night before you decide to make this,take your air tubing and cut a 3 1/4 inch piece off,
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take your aquarium sealent
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and put the tip in the tube,squeeze in sealent about 1 1/4 inches in and let dry overnight,

step 3--making the probe
!caution! after you solder the length of wire to the board bust the little metal dot off the bottom of the thermo Case and put the other end through the hole on bottom
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ok now time for the little blue piece from earlier that you unsoldierd off the board ,get you multimeter and turn on the thermo,touch the black probe to the neg side of the the thermo battery and touch the red to each of the length wires(which ever number shows highest is your positive) now that you found out which one is posi turn off the thermo and connect the posi to one side of the blue piece and the neg to the other,now turn on the thermo with the blue piece connected to the wires ,if it doesent give a temp but instead a diff screen turn off the thermo and switch the wires around,when you get it to turn on and sense temp(take it into you grow room and match it with your thermo in there to make sure) you dont have to soldier the blue piece onto the length of wire unless you want to,you can wrap the pos and neg from the length of wire around either end of the blue piece like so.
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and tape it(try to get as much bare wire taped as possible but DONT get tape on the blue head ,now that your sealent has cured you can make the probe,take the blue headed piece and cram it in the tube but keep it at least 1/4 inch away from the sealent,after put in the tube the probe measured 1 3/4 inch in the tube
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now that the blue headed piece is in the tube it is time to test again.take it back to your grow room and compare again if it works its time to water proof it.take the sealent and shove the tip in the bottom and squeeze some in until it looks good(you might have to squeeze a lil on each side of the wire to get it good and packed but i dident have to,
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let the packed sealant dry while you put the thermo board back into the case and put the screws back in,let sealant sit for at least 2 days minimum,ok i hope im not forgeting anything,but if you have any questions just ask,,,

for the next part of this thread me and fpf will show you how to make a res cooler..stay tuned :bong:
 
You know this is a trip. I mentioned in passing that I needed to build a diy res cooler because my temps were too high. I felt this could work in a pretty basic fashion. But what it really needed was a thermostat to take it to that next level, make it work on it's own. With a thermo I could sit back and let it do more of the work.

So what does he do? He builds one.

Any input will be appreciated, this is an incredible start.
 
Holy crap Batman! This is a piece of work! This is a really sweet piece of hardware. I need something to turn my my res cooler on and off as needed. I have to admit, I'll need to re-read this tomorrow, but if it works as advertised, well I'm extremely impressed!

Keep it up bro, you're going places here! you've got a very creative mind.

o yea i forgot to give you the link to the temp controller (we have to take the probe we made ,open the controller,cut the temp reader off of the controller and hook up our probe to the controller,,ill get it first just to make sure it is possible,because of the variety of thermistors its hard to know what it has in it,but even if it doesent work for the one ive got made i can always try and make it work,basicly it would be the same concept(extend the thermistor off the board into a plastic waterproof tube)here is that website.Greenhouse Controls - Thermostat Controllers from ACF Greenhouses ,im ordering one so here is the order number,grand total ..ect--order #4820400

SureSTAT T110 Single Stage Thermostat $34.95 ea. 1 $34.95

Order Subtotal: $34.95
UPS Gnd Residential [62896] Shipping: $12.11
Grand Total: $47.06
 
o yea i forgot to give you the link to the temp controller (we have to take the probe we made ,open the controller,cut the temp reader off of the controller and hook up our probe to the controller,,ill get it first just to make sure it is possible,because of the variety of thermistors its hard to know what it has in it,but even if it doesent work for the one ive got made i can always try and make it work,basicly it would be the same concept(extend the thermistor off the board into a plastic waterproof tube)here is that website.Greenhouse Controls - Thermostat Controllers from ACF Greenhouses ,im ordering one so here is the order number,grand total ..ect--order #4820400

SureSTAT T110 Single Stage Thermostat $34.95 ea. 1 $34.95

Order Subtotal: $34.95
UPS Gnd Residential [62896] Shipping: $12.11
Grand Total: $47.06

Okay, now I'm too high. I'll re-read this tomorrow morning! Those margaritas are pretty damn good.
 
Okay, now I'm too high. I'll re-read this tomorrow morning! Those margaritas are pretty damn good.

ok thats cool,but yea this shouldnt take but shipping time to come together,im going to order it tomarrow morning that way it will leave out the same day and i might get it sooner,,o btw ,have you found anything out about the res tubing(size),?
 
Some tech skills this is the stuff I like to see. Never have used a Soldering iron before, well not yet at least. This is book-marked :)
 
well i think i have it figured out,i ended up putting the heat exchanger(metel piece that makes fridge cold)in the water bucket,,i had to put 32 degree water in the bucket with some ice becuase it took too long for the exchanger to catch up with the flowing water and heat from the water pump,but starting with freezing cold water takes 1 gallon of water from 75 degrees to 60 in less than 10 min,,i made the mistake of using 3/8 inch tubing(you will need 1/2 inch diameter air line tubing(thin stuff) . the thinner the tube the more cold it should radiate off of it,it is still in progress and im still waiting on a part to toy with so here are some pics and ill finish this when i get that part,,
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inside i have frozen stones under a computer fan for a little bit cooler air im going to get some 1/2 inch tubing and extend the chiller out of the room because the fridge heats up and i dont need the extra heat,also,i put a thermo in the retun tube before it goes back in just to see if i keep a consent temp or if the res water will heat it a bit before returning it,but thats all for now
peace:roorrip:
 
thank you for the tip I just did one to an acu rite in/ out that I had. I used the remote box as the water probe unit and can see my res temp on my desk yeaaaaaa. but I have a small problem I put about a 4 ft lead on mine so I could get the box up outta the way. my temp is reading about 12 degrees f warmer than my cheap fish themo in the same tank. is it possible since it reads resistance to current I believe, that too much wire will alter the temp reading of the probe. it was accurate before. should I drop it down to a 2 ft lead.

thanks for your innovation
 
thank you

I had to cut bact to 2 ft wire remove the aquarium tube, and just waterproof the legs of the sensor. found a dial but no luck. think it might be the thin clear wire I used maybe it is being affectef by the heat and skewing the number. out of water it is within 1 degree nost of the time but in water its back to way off. did find a lacross unit with remote probe yada yada yada on sale for 19 shipped so I ordered that but will still tinker with this one to try and "figure" it out lol again thank for your help
here is the link if anybody needs a new one
LaCross Themometer

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this is the cheapest I have found a water temp with remote sensor. cheap as most air temp units lol
 
wow its been awhile since ive been on,thanks to prairie for helping dark,but yes i think the length of the wire would have alot to do with the temp diff between the 2 thermos,if your wanting distance i would go with a remote,im still reserching different thermos and applying differnt methods to my work ,more will be revealed soon`and thanks climate,
 
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