Digital Cat Probe

[mellow]

My cat looks the same as it did when I first bought the stove last spring and I even had that cat over 2000 degrees due to the ash pan leaking air, that is fixed now but the cat was not affected. I have no problem running a steel stove hotter than one of those VC's.

 

[raybonz]

My cat looks the same as it did when I first bought the stove last spring and I even had that cat over 2000 degrees due to the ash pan leaking air, that is fixed now but the cat was not affected. I have no problem running a steel stove hotter than one of those VC's.

I look at this way I don't my car at redline and I don't run my stove this way too.. It's up to you in the end..

 

[mellow]

Auber is in, will install it tonight to try it out and get some pics.

 

[mellow]

Guess I won't be testing the at100 tonight, auber did not ship the power supply with it like they were supposed to.

 

[claybe]

Wow! I learn something new here everyday. I had no idea there was such a thing as wireless cat thermometers! Sweet! Can't wait to heat the results.

 

[mellow]

Got the power supply in yesterday and have been running tests yesterday and today, the supplied thermocouple is not reading cat temp correctly, I am going to put in a service request with Auber to see what they have to say. I am noticing the Auber will read 1000 degrees on the cat when the Condar will read 1500, quite a bit of difference and I believe the Condar is reading correctly.

 

[Ashful]

Interesting! Same exact location? Same probe length? To be honest, I just take my K-type thermocouples at face value... I have no real way to verify them at those temperatures.

 

[mellow]

Now that I am back to work I can post the pictures and message I sent to Auber.

The power supply for the AT100 arrived yesterday and I was able to test it out, I have found that it is not reading the temps correctly, I am wondering if the 6" probe is to short? I have tried placing the probe in several places around the cat and even in the cat, placing it in the cat gives me the highest readings which is still not correct (too cool). I have attached pictures of my setup and how I am using the 6" probe and a picture of the AT100's temp reading and then a reading from my existing Condar temp probe so you can see the difference in temps, they were switched out very quickly several times with the same results each time. The Condar is correct in temps due to the cat was glowing and other temps I took around the stove point to the 1500+ degree reading being correct. As you can see from the one picture of your probe you can see how much of it on the end is getting into the cat, is that enough to record correct temps, is that why I am seeing a cooler reading? Should I be using a 10" probe?

Btw, the horseshoe magnet I have holding the wire up is not affecting it, I tried it without it and got the same temperature results.

The reply back from Auber is it should work. I think I am going to be on my own on fixing this issue, my next step is to test other things to make sure it is calibrated right.

 

[mellow]

Man, those Omega thermocouples are not cheap, looking at the TJ36-CAXL-14E-12-CC and it is $53 before shipping!

I am thinking I might try getting the 10" ver of this same thermocouple from Auber, I really do believe it is not sticking in far enough into the cat to get a correct temp, only about quarter of an inch of it is touching the cat.

 

[mellow]

Interesting! Same exact location? Same probe length?

The Condar is about a quarter inch longer than the Auber probe, but it is put in the same spot.

 

[raybonz]

The Condar is about a quarter inch longer than the Auber probe, but it is put in the same spot.

On my CDW the Condar cat probe did not go into the cat but sat just above it.. Keep in mind that some areas of a cat may be hotter than other areas..If possible locate the cat probe towards the center of the cat.. I say this because I could lift the cooktop while the stove was running and see the orange glow but not everywhere.. You may be seeing this on your cat..

Ray

 

[mellow]

It is the same way with mine, my Condar sits on top (where the gasket is pushed back) and reads correctly but when I put this Auber in the same spot it reads 200 degrees cooler than if I insert the probe directly into a cat cell, which it still reads cool compared to the Condar. I have tried putting it in different areas of the cat with the same results, I hope I haven't messed up my cat to bad as you can see from the pic I have messed up some of the cells with putting this probe in some of the different areas.

 

[Ashful]

No problem with using a longer probe, mellow. In fact, it will increase the likelihood of your probe's survival. Omega suggested going with a longer probe, if I was close to the temperature limite of the probe/wire junction. They can always be bent to a right-angle at the length you need. I'm currently using long (10-12 inch?) probes bent at 3.5" from the tip.

 

[mellow]

I can't believe more people have not switched to using a digital cat probe, even though this one is not working 100% yet it is still great to see the cat lighting off in real time and watching the temperature climb so you know for sure it is lit, it is also nice to be able to see the temp from 20 feet away in the kitchen. I should have done this sooner.

 

[mellow]

Took a shot of the two probes last night, yes yes, crooked, the Condar had just come out and it was burning hot, wasn't exactly trying to handle it to much. But anyway you can see how the 6" probe isn't as long as the Condar. I will go ahead and order that 10" probe.

 

[Ashful]

I can't believe more people have not switched to using a digital cat probe... I should have done this sooner.

Yep! Being a scientist who uses thermocouples regularly for my job, it's all I've ever used.

I'm not sure of the refresh rate on the hand-held thermocouple meters I've been using on these two stoves (Amprobe), but it seems to be somewhere in the range of 0.5 - 1.0 seconds. If after engaging the catalyst, I see the temperature jumping by 10 - 11 degrees per refresh cycle, I know I'm going to get good light-off. If it's only jumping 7 - 8 degrees per refresh cycle, not good. Saves me the time of sitting there and watching it climb all the way up.

Also, on some mornings when the stove is a little more reluctant to come up and light off, I can set the recording feature, and see what the stove did when I get home in the evening. I'm learned a good deal from reviewing these recorded max and average temps, such as when it's okay to leave it just hanging at 550F on the catalyst, instead of having to go back to bypass and toasting the wood some more.

 

[mellow]

Got the order in for the 10" probe, I had looked at the kiln probe with a ceramic cover but that sucker is huge, 3/4" at 12 inches long I think that would be impossible to fit it above my cat, it would probably last for years however.

 

[raybonz]

No problem with using a longer probe, mellow. In fact, it will increase the likelihood of your probe's survival. Omega suggested going with a longer probe, if I was close to the temperature limite of the probe/wire junction. They can always be bent to a right-angle at the length you need. I'm currently using long (10-12 inch?) probes bent at 3.5" from the tip.

Personally I would get the length required as I feel the excess probe could dissipate some of the heat and possibly skew your readings.. If you have a way of calibrating your probe such as pyrometric cones or an infrared temp gun you could base your temp on that and if your temp controller has an offset adjustment you could trim up or down according to the actual temp..You may find your Condar bimetal tstat is way off and generally those are most accurate in the middle of the scale..

(broken link removed to http://www.standardceramic.com/PyrometricCones.html)

Ray

 

[mellow]

So I have been playing with the 10" probe over the weekend and have come to the conclusion that it is WORSE than the 6" probe. It is thicker so it will not fit into the cells of the cat so I have made it into a J shape so as much as possible of the probe is over the cat, exactly where my Condar probe sits on top of the cat.

I can't explain it but it seems this probe doesn't like to read from the probe tip but rather gives more emphasis from the beginning of the probe, I can only get it to read in the 1000 degree range if the fire is active right against the glass of the door which would be directly right under this probe, the rest of the time it is in the 600-800 degree range which is really off, I KNOW that cat is in the 1200+ degree range, but these stupid probes will not read it no matter what I do. Frustrating to say the least.

Anyone found a working solution?

 

[Ashful]

My setup is completely different than yours, with the cat drafted vertically behind the firebox, but the Omega probes seem to be working for me. The McMaster ones work as well, but burn out after a few weeks. Length does not seem to matter in my case, as I've tried them all, with always the same results. I'd be highly suspect of the quality and accuracy of ANY thermocouple probe costing under $30. That's just what they cost / maybe you get what you pay for.

 

[mellow]

Post some pics of your setup.

 

[mellow]

My next step is to order the probe from Condar that fits their digital temp reader.

(broken link removed to http://www.ebay.com/itm/Condar-Digital-Catalytic-Combustor-Monitor-Wire-and-Probe-Fireplace-Insert-/281048249454?pt=LH_DefaultDomain_0&hash=item416fc7f46e)

For kicks and giggles I look off my flame shield on my cats so I could get a better look and try putting the probes in different spots, did no good, still only goes up to about 900 degrees.

 

[mellow]

Man I can't catch a break with this whole thermocouple reading a cat deal. Got the Condar thermocouple in, reads about the same as the thermocouples from Auber no matter how I put it on top of the cat. Not sure what to make of this.

Condar does say that their thermocouple should go BEHIND the cat, that would be about impossible with my setup unless I drill through the top plate of the stove, then that also puts me in the same position as Joful's downdraft setup, I would not get cat temps till I CLOSE the bypass.

I am about to throw the towel in on getting a working Digital Cat probe.

 

[Ashful]

Mellow,

I'm not sure I follow what you're saying. Don't all cat probes have to go downstream of the cat? If you're putting it upstream, you're not really measuring cat exhaust temperature, which is what all manufacturers seem to reference in their literature. Perhaps your stove is just not designed to have a cat thermometer?

I think I know why you were asking for photos of my setup, now. I don't think a photo will help, but I can sketch the setup tonight.

 

[mellow]

Buck, Appalachian, High Valley and many others with a top front mount cat all take readings from the front top of the cat, the hole for the probe is just above the door on most models.

What is weird is my 6" Condar probe reads the cat temperatures just fine, I can't and Condar can't understand what the difference may be (Thermocouple vs Bimetallic) in the same spot. Both probes in the same spot should read the same temps, in theory.