Thermometers & Thermocouples

[Aces High]

Hi All,

I was recently using my my thermometer with 2 probes plugged in. both were in the same boiling wort pot and reading 3 degrees apart, when I pulled out one probe the reading on the other one raised by 2 degrees, when i plugged it back in it dropped.. It is so hard to get an accurate thermometer ?

Ive got access to these temperature sensors RKP6 fairly cheaply. They are PT1000 immersion sensors. I currently have a twin input K-type thermometer and I was thinking if i attached a K type plug these would work with my current thermometer.... they don't.


After searching around the internet and reading about different types of thermocouples etc I still can't find if there was just a basic thermometer available that uses them. I have found that they are 1000 ohm resistance and are used on solar hot water system controllers.

Being designed for immersion they could be very handy for fermenting & mashing.

Any help would be appreciated.
.

 

[billygoat]

If you want a reasonably priced and accurate digital temperature measuring device, look at the Hanna Checktemp. They are available for around $50 delivered from the US. A seller has them on Ebay, I bought one awhile ago from him and it is accurate and works well.

 

[Diesel80]

Any help would be appreciated.
.

These may or may not suit:

i use the automotive guages from these guys
http://auberins.com/

Cheap, sell all sorts of thermocouples and the automotive guages are compatible with plenty of input types.
Seem accurate enough monitoring boost and exaust gas temp in my landcruiser, not sure how they will go with beer making....

Edit:
Just had a closer look, they actually sell a thermocouple designed for get this, beer making or biodiesel production (is that another name for kit twang?).
http://www.auberins.com/index.php?main_pag...products_id=108


Cheers,
D80

 

[Aces High]

Well after a bit more research it looks like the sensors i have are RTD's Positive tolerence 1000 ohm sensors. As opposed to thermistors (negative tolerance sensors) that are used in an STC1000.

Thermocouples are something different again and are based on voltage between two different types of metals rather than resistance. Its amazing how much research you can do when you should be working.

 

[leiothrix]

It is working! Just on more important things (to you, of course).

 

[mILLrAT]

It is working! Just on more important things (to you, of course).

Thermocouples are generally for higher temp applications up to hundreds of degrees. Rtd's operate in the range for brewing temp control. I have had identical units next to each other and they can have 1-3 degrees difference. I prefer the Dallas one wire device via a Arduino controler. Even then you need a reference thermometer to calibrate all the others.