Measuring Temps

[Rob_Red]

Hey All, I apologize if this has been beaten to death already but what is the best way to measure temp on my Green Mountain 40 catalytic stove? Currently I am only relying on the built in catalyst probe that tells you when to close the bypass and I don't think I'm getting enough information.

Would a pistol grip infrared thermometer be a good choice for measuring the stove top? I know the old standard is the Midwest Hearth magnetic thermometer but with the availability electronic thermometers its hard to not be drawn to an instant read out from anywhere on the stove.

I have read the "how to start a fire" thread and will start using the East/West method, however I still need to connect some dots....

My plan is to use the built in catalytic probe to know if the cat is ready for the bypass to be closed, and from there monitor the stove top and keep it around 625 degrees.

Does this seem like a good strategy? Would monitoring flue temps help me in any way?

I appreciate everyone's input.

 

[gthomas785]

I like to use an infrared gun in combination with a flue probe thermometer. Those two will tell you pretty much everything about how the stove is running at any given time

 

[Rob_Red]

I like to use an infrared gun in combination with a flue probe thermometer. Those two will tell you pretty much everything about how the stove is running at any given time

What does one look for when measuring flue temp on a cat stove? I always thought the cat made the flue temps lower than a non cat stove and never really understood the purpose of measuring.

 

[gthomas785]

What does one look for when measuring flue temp on a cat stove? I always thought the cat made the flue temps lower than a non cat stove and never really understood the purpose of measuring.

Well I dunno if your cat stove is very different from mine (I have two VC stoves) but my cat probe never registers anything until after I've closed the bypass. So after I load up I usually wait for the flue temp to be 500-600 then shut the bypass and wait for the cat to respond. That's the main time I'm looking at the flue probe, but it'll also tell me if I've shut the air down too fast when I see the temp falling shortly after a reload. I also use it for peace of mind to know that I'm not overfiring etc.

I did get by my whole first season with just the IR gun. That alone will tell you a lot.

 

[begreen]

What does one look for when measuring flue temp on a cat stove? I always thought the cat made the flue temps lower than a non cat stove and never really understood the purpose of measuring.

Mostly you want to watch that the flue temps stay within a comfort zone. Not too cool (above 300º) during the active flame part of the fire and not too hot once the cat is engaged which would be a waste of fuel. The range is going to be stove and flue system dependent. A cat stove with a straight-up interior flue system is going to be safer running cooler flue temps than one connected to a cold exterior chimney.

If the stove has double-wall stovepipe then a probe thermometer will be required. I particularly like digital probes, but an analog one will suffice. If the stovepipe is single-wall then you can do a surface reading and double the reading. An IR thermometer in this case would be fine. The advantage being that the IR thermometer will be more accurate. The disadvantage is that you can't tell the temp at a glance while walking by the stove.

 

[Rob_Red]

If the stovepipe is single-wall then you can do a surface reading and double the reading.

What is the reason you double the reading? Are the gasses hotter in the center of the pipe?

 

[begreen]

What is the reason you double the reading? Are the gasses hotter in the center of the pipe?

Yes approximately. This doesn't work with double-wall stove pipe. The outer jacket buffers the heat.

 

[logfarmer]

What does one look for when measuring flue temp on a cat stove? I always thought the cat made the flue temps lower than a non cat stove and never really understood the purpose of measuring.

When my “cat” englander stove is running a stove top temp of around 450-500*f, my pipe thermometer is running about 230*f (single wall pipe) which is about 18-20” above stove top on the pipe. Gives you an idea, I’m burning seasoned wood and pipe and chimney is clean.