Non-contact Thermometers

[therook]

Interesting, so buying the cheapy infra-red thermometer has allowed me to realise that that stick-on strip thermometer on my fermenter was actually completely broken, doh :blink:

Bit worried about the accuracy though, has anyone got any ideas on a way of testing a thermometer without using another? ie an object/liquid with a known temperature at a particular state?

I also have worked out that my stick on fermenter Temp gauge is completely up **** creek, it was showing 24c in the fermenting fridge while my fridge mate was showing 19c, i them compared the 2 with the temp guage i bought from Ross for 12 bucks and it also showed 19c

Ross

 

[tangent]

that's the whole reason I'm looking into it. those stick-on's suck arse!

 

[monkeybusiness]

If you want a good thermometer then these as they are getting good reviews on brewboard and it may be worth looking at a bulk buy?
http://www.labsafety.com/store/Lab_Supplie...isredirect=true

I would be interested in a bulk buy situation. I'm getting together the last of my AG gear and a good mash thermometer is on the list. That one looks pretty good if you say its getting good reviews. Sorry if this is going off topic. If anyone else is interested maybe we can start another thread...

 

[tangent]

DrGonzo uses them and can't say enough good things about them.

The stick type from Ross at Craftbrewer has been a good buy as well.

 

[drsmurto]

OT but these are the thermos I was give the heads up on.

Link

0.2degC accuracy. Altho losing 4-5C doing a one hour mash this kind of accuracy is overkill......

 

[LethalCorpse]

The things to look out for when considering a thermometer or temp sensor are linearity and repeatability. You want minimal drift with pressure, humidity, operating life etc. And you want as close to perfect linearity between 0C and 100C. If you get both of those things you can calibrate it yourself - either with a formula that you calculate each time if it's a manual readout, or in software/pots if it's a voltage output that you're using with a DAQ. Calibration is as described by NewGuy

 

[PistolPatch]

Nope Pat, I don't get any variation when I use it to check the fermenter, but then mine cost $150 odd. I originally would put a little patch of black insulation tape on the fermenter, but it hasn;t really proved to be necessary. You do have to do that if measuring something shiney like stainless though otherwise it gets confused about the reflection. You can also calibrate the non-contact one against the k-type probe as well, as they will display at the same time on mine.

Tangent, I think I made a very bad post!

Domonsura's post above got me thinking and so I dug out my infra-red thingo after doing two brews on Saturday. It's the Jaycar Digitech QM-7223.

As mentioned in my last post, the thermometer measured the outside of a cube just filled with water consistently. This got me further thinking.

I just took some measurements of my two fermenters and the variances I said I got in my last post are certainly nowhere near what I quoted. Here is what I just got - 3 days after pitching...

Brissy Brew's fridge controller probe reads 15 degrees and the probe is in the pale ale fermenter.

Pale Ale Fermenter: The reading is consistent at 15.6 degrees whether I measure top or bottom of fermenter. This brew is past high krausen.

Kolsch Fermenter: Reading at top of fermenter is 15.2 and at bottom is 14.6 degrees. I pitched low on this as I only had one pack of yeast between my fermenter and a mates so split it in half and it is in the middle or start of krausen (at last!)

I'm not sure why my memory of my early use of the infra-red is so negative??? I used it on my first brews (possibly kits) and maybe these fermentations were more violent than I get now.

Anyway, I feel now as though my negativity and figures in my prior post have been very misleading. (I still stand behind my comments on thermometer accuracy though Checking your thermometer at freezing and at boiling does not guarantee the readings in between unfortunately.)

Anyway thanks Domonsura and Tangent for making me drag this expensive bit of equipment back out of the cupboard. The next jobs for it will be working out a way to measure the strike water and mash temperatures hopefully accurately. I tried it on the sticker of my pot the other day but didn't get close Not too sure what the answer is to that.

My apologies for my inaccurate memories,
Pat

P.S. I'll put a note in my previous post at the start so as any future readers will know to ignore what I wrote

 

[tangent]

well, my gf's bro did a good thing and scored me an expensive gun type one for $45!!
It's freakin awesome! we've ben testing arses, armpits, you name it!
My stick on thermo was WAY off! Useless!
More details soon.

 

[LethalCorpse]

well, my gf's bro did a good thing and scored me an expensive gun type one for $45!!
It's freakin awesome! we've ben testing arses, armpits, you name it!
My stick on thermo was WAY off! Useless!
More details soon.

Don't forget to sanitise...

 

[PistolPatch]

I must admit I had a lot of fun when I got mine doing the above (measure your wrist for example.) Thanks to this thread I got it out again the other day. Here are some non-brewing related measurements when the weather bureau here measured 40.4 degrees...

Bitumen in full sun - 78 degrees
The car seat cover on my van in full sun - 86 degrees (not sure why this read higher than bitumen???)
The coolest part of the interior of my van - 60 degrees

For me, this explains those days when I feel drunk (or at least punch-drunk) before I have a single beer. Driving in my van is far more exhausting than working!

:wacko:
Pat

 

[TidalPete]

http://www.labsafety.com/store/Lab_Supplie...isredirect=true

That looks like the cheaper version of the one I got from Control Company HERE
I got the model 4339 (+- 0.2 deg c) some time ago & found that after 6 months or so of use that the cable (where it joins the plastic bit on the probe) split because the heat from the mash tun was too much for it. The thermometer is guaranteed for temps between -50\+300 deg c but the part where the cable joins the probe is not.
The result was a stuffed thermometer so be aware that all is not what it seems with these thermometers.
Managed to get a replacement off Control Company last week & am hoping that a bit of heat shrink tubing over the dodgy join will solve the problem? Has anyone got a better idea??

TP :beer:

 

[RobB]

I've just been using my non contact thermometer on my fermenter which is in an esky with frozen bottles. Now that the yeast have stopped throwing out heat, the whole system is starting to cool down. I was amazed to find that bottom of the liquid was six degrees cooler than the top (13 vs 19). I checked at several points around the circumference and kept getting the same result, so it wasn't a local effect due to the frozen bottles touching the fermenter. I don't know if this is good, bad or indifferent but I had a lot of fun turning on the laser sight and blasting away.

 

[LethalCorpse]

tell the truth now, did you make gun noises? Maybe try a quickdraw?

 

[tangent]

It had got a cool holster

 

[RobB]

tell the truth now, did you make gun noises? Maybe try a quickdraw?

No, but I did put on my Spock ears and set it to 'stun'.

 

[PistolPatch]

I've just been using my non contact thermometer on my fermenter which is in an esky with frozen bottles. Now that the yeast have stopped throwing out heat, the whole system is starting to cool down. I was amazed to find that bottom of the liquid was six degrees cooler than the top (13 vs 19). I checked at several points around the circumference and kept getting the same result, so it wasn't a local effect due to the frozen bottles touching the fermenter. I don't know if this is good, bad or indifferent but I had a lot of fun turning on the laser sight and blasting away.

Agh!!!

Maltycultural is a very trustworthy poster here and I have actually had the pleasure of meeting him once on a brew day at my place. The beer he brought along got awarded best/most enjoyable beer by a self-elected panel headed by myself :icon_cheers: (No, it was an informal discussion after most participants had left so our panel of 4 could talk honestly. Malty won hands down - no tricks here - a brilliant beer.)

Agh????

Malty I'm hearing you brother! I think you have just explained everything for me - things that I had forgotten...

I used to ferment in a 65lt esky that sat above my dispensing fridge. I used to sit the fermenter on about five freezer blocks (not 4 or 6 believe it or not - another story.) All makes sense now!

This I now see was the cause of my prior weird measurements.

Trying to think of an intelligent way to end this post but I have had a few beers with some other AHB'ers in the not too distant past of some minutes

Anyway, from what I can gather, top post MC.

Thanks,
Pat

Edit: Should have added in here somewhere that the jug of water I put in the freezer section of my fermenting fridge/freezer has frozen but the glass of beer has not. So, it looks like this section runs at about minus 2 degrees - not real handy.