K Type Thermocouple

[AndrewQLD]

HI
I am looking for a k type thermocouple (i think) I have just purchased a BTC-9090 controller and I need to get a temp probe to go to my HLT, can anyone point me in the right direction and if possible give me any tips in setup/usage. (I am technically impaired)

Regards
Andrew

 

[Fammer]

You can get them from Jaycar & **** Smith etc for around $10 but the length of wire is pretty short, I am sourcing some 'special' extension wire to make them longer.

I currently have a few controllers just got to get a 24v power pack and then I will be looking to buy around 4 Thermocouples.

Possible AHB group buy?

 

[vlbaby]

The 'special' extension wire you're referring to Fammer, can be used as the sensor itself if you want to save a buck. Just twist the pair of wires together, solder them if you wish, then at that point it becomes your temperature sensor.

vlbaby.

 

[Fammer]

ahh vlbaby - good man!

Friend has some offcut supposed to be coming when he gets back from where ever he is.

Is it accurate though? I know thermocouples are not that accurate and usually a few degrees out - does this make it worse.

 

[Gout]

i was told they tig weld the ends together in the "real" ones, so i assume twist may also sorta work... however i think the voltage given (as per temp) is due to different metals hence the K type P type N type etc and the solder may (or may not) effect this??!?! (another metal)

I do not know enough to say what to do, just as i am having a home brew after work, i thought i would through this somewhat usless information in....

sorry and back to drinking

 

[vlbaby]

It's exactly the same accuracy as any other probe as long as you use the correct type lead ( Compensation lead ) , you'll be fine.
You're right about the accuracy, thermocouples can be a bit touch and go with accuracy. In my experience +/- 1 deg is common. But this shouldnt present too much hassle as most temperature devices can be fine tuned to read correct values.
I use one of these setups on my brew fridge, and it serves the purpose ok. Much better than a thermostat i can tell you.

vlbaby.

 

[vlbaby]

you could be right about the solder bit gout. I havent soldered mine, but i have done it before for installation i have done at work. I dont' remember having any problems, but if you were unsure, it is easy enough to do a comparison between soldered and just twisted.

vlbaby.

 

[als_world]

I have just purchased a BTC-9090 controller

Ah, so you're the one that won the auction (I should have know from the eBay bidder ID :blink: )

As other posters have said, you can make your own K-type (as oppsed to K-tel ) thermocouples from Chromel and Alumel wires/strips, but it's generally easier to buy the off-the-shelf ones.

Have a look here -> http://www.isi-seal.com/searchs/doc/ThermocoupleIntro.htm for descriptions of the various thermocouple types/materials.

The BTC-9090 can use most of the common types of thermocouples, but you'll need to program it to take the right one. You'll want to start here -> http://www.brainchild.com.tw/bc/index-product_c_9090.html and read the PDF manual. You'll also want to check the part number to see what options it has for inputs, outputs etc. It's a good unit and you've done well on the price, but you may need to set aside a bit of time to configure it correctly.

Cheers,

Alan

 

[ausdb]

The 'special' extension wire you're referring to Fammer, can be used as the sensor itself if you want to save a buck. Just twist the pair of wires together, solder them if you wish, then at that point it becomes your temperature sensor.

[post="58592"][/post]​

i was told they tig weld the ends together in the "real" ones, so i assume twist may also sorta work...

[post="58604"][/post]​

Gouts correct on this one, a welded joint will give a better reading than just twisted or soldered wires

I have fixed thermoucouples before using a car battery and bit of the carbon rod from an old D cell battery using a method described at the bottom the following page.
http://yarchive.net/electr/thermocouples.html

HTH

Ausdb

 

[AndrewQLD]

Thanks for all the replies,
found the one at DS for $10.00 and I think I might go with this
http://dseau.resultspage.com/search.php?se...rmocouple&site=

I did win that one Alan, and have downloaded the manual, by the looks of things I have a lot of study to do. :blink:
regards
Andrew