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Post by jonnycj on Mar 30, 2012 19:41:38 GMT
I'm thinking of building a temperature probe into my wfo. Does anyone have any recommendations for a suitable sensor and gauge that can withstand the heat ?
Thanks
CJ
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Post by scottme on Mar 30, 2012 22:10:49 GMT
You might want to build thermocouples into the body of the oven. This is the high tech approach that a few of us have considered but I don't think anyone has actually gone for it. I costed it out at a few hundred quid (for I think 3 thermocouples and the gadget that they plug into), and decided I had other things to spend my money on  A pretty common approach is to fit a dial thermometer to the oven door, with a probe that extends back into the oven: this will allow you to check the temperature before and during bread baking and other door-on cooking, but that type of thermometer won't handle the kinds of temperatures you need for pizzas, not that you'd even have the door in place for that. For pizzas, I think the simplest approach is to get a direct reading infrared digital pyrometer - they're readily available on eBay for about £20 or less, and will handle temps up to about 500°C or more. |
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Post by jonnycj on Mar 31, 2012 9:12:46 GMT
Just bought a temp sensor and digital readout gauge on eBay for about £15 all in. Should read out up to 999deg c.
I'm thinking of drilling into one of the fire bricks and positioning half way up the roof. Should be a good indicator if not exact.
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Post by cannyfradock on Mar 31, 2012 11:16:14 GMT
Hello Jonny Thermocouples have been used quite often in our (members) builds over the last few years. They are not so expensive and can be placed in the floor and the dome. I will try to find some archive stuff for you to use as reference. ......just in case ....if you go on our old forum, look through the categories AND also type in some keywords into the search facility (at top of page in blue letters)...forum link.. woodovenukforum.forumup.co.uk/index.php?mforum=woodovenukforumTerry |
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Post by cannyfradock on Mar 31, 2012 11:26:30 GMT
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Post by jonnycj on Mar 31, 2012 17:01:28 GMT
Thanks Terry
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Post by tonyb on Apr 1, 2012 12:05:18 GMT
Like others, I considered using thermocouples but decided against it mainly based on cost, (its not just the relatively small cost of the tcs but the datalogger needed) as I think you probably need an array of 6-12 as a minimum. I doubt the usefulness of a single thermocouple, other than as a spot reading. If i was using a wfo commercially I would seriously consider thermocouple monitoring.
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nef
member
Specialist WFO fuel supplier
Posts: 12
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Post by nef on Apr 1, 2012 15:05:53 GMT
In respect of a commercial WFO, a major american manufacturer, Woodstone, use a single thermocouple based in the centre of the base stone. This is a replaceable item as shown on page 13 of this installation manual www.woodstone-corp.com/pdf/manuals/install_w.pdfThe thermocouple has been shown to be very reliable and repeatable. Excellent ovens used by restaurant chains Zizzi and Piccolino. No reason not to install a thermocouple at home other than you need a power supply! Many commerical chefs use a non-contact thermomometer such as a Raytemp 3 (500 degrees C) with laser spot. Much cheaper alternative to a thermocouple and found to be just as reliable. |
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Post by tonyb on Apr 2, 2012 9:41:08 GMT
The problem with only using a single TC is that it assumes that the whole of the oven space is the same temperature. This may be ok for a commercial wfo where the the oven is probably soaked with heat daily, but not for a domestic set up with intermittent firing.
My personal view is that if you are going to the trouble and cost of a TC setup you might as well do it right or not at all, particularly when there are cheap alternative methods of estimating temperature.
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Post by Calaf on Apr 2, 2012 10:38:07 GMT
Totally agree with Tony. Even after 2 hours firing you can have a 300'C differential between top and bottom. I bought an IR laser pointer type thermometer for £12 and find it is more interesting than genuinely useful.
You could buy a few K type thermocouples and bury them in the mass. They are quite cheap but you need the high-temperature ones. These could be connected to a cheap multi-meter or a laptop.
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Post by DuncanM on Apr 2, 2012 12:56:17 GMT
I've read a few places (can't remember if here or elsewhere) that people use a few K type thermocouples and use a cheap battery powered multi meter for their readings. I did enquire about getting some 100mm dial temperature gauge's, but at £200-£300 each I decided I'd rather eat my own firebricks  Maplin sell the thermocouples for about £5 a pop, and a basic battery powered multimeter can cost about £30. If I ever build another oven (moving house etc), then I will definitely install thermocouples. |
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Post by cannyfradock on Apr 3, 2012 19:47:16 GMT
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tapir
valid member
Posts: 45
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Post by tapir on Apr 16, 2012 17:00:46 GMT
I deliberated about this for ages - not only will it be useful to see exactly how my oven performs, but I do like to geek out with tech The cost of thermocouples and a reader initially put me off, and when I thought about it, I realised that one thing I am really enjoying about building my oven is that it's tech free - proper old school! I decided that (when it's complete) I'll do what I can to learn how my oven runs. If I do make one tech purchase, it will be an infra-red thermometer so that I can see how hot the oven gets. |
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Post by turkey on Apr 16, 2012 17:19:59 GMT
agreed I even investigated making my own logger from bare bones components but even the cost of these was prohibitive.
ir thermometer here I come :-)
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Post by dougclay on Apr 18, 2012 18:58:50 GMT
I bought a couple of High temp Thermocouples (£4 each) from Hong-Kong at the end of last year and a dual input Digital Thermometer £20 incl p/p that shows both Temperatures, highest, lowest, average for each and the difference between the 2....
I've also looked into self build data logger (using ready made components) but these were limited to fairly small temperature ranges... I'll look into this again when the raspberry pi finally turns up ;-)
I'll be retro-fitting my clay oven in the coming months, just got to find a drill bit long enough to get through all that clay.... as for the floor, I never stuck the bricks down, and although they are currently looking very neat on settled, I might pull them all out and refit on top of something more insulating than the bricks and sand I used underneath originally... if I do, I'll put a couple of k-types in the floor too..
This is all just for geeky nerdyness though... after you have used a wood oven a few times, you just know when it is hot enough ;-)
but it was interesting to see the the temp edging towards 800C during the Bonfirenight firing....
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