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Member Posts: 4,052
I'm just curious. What's everyone's oxygen reading when you start up your combustion analyzer? Ours is 20.9%.
8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

Two btu per sq ft for degree difference for a slab

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Me 2, on both a Bacharach Insight Plus, and a UEI 155.
When I'm done taking a reading I usually let it run until i have 20.9% 02 & 0 ppm CO before shutting it down.

There was an error rendering this rich post.

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So do I. I'm told it clears the CO sensor and makes it last longer.
8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

Two btu per sq ft for degree difference for a slab
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20.9 is the number
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If the probe isn’t in flue pipe, that’s what you’re going to get.
Steve Minnich
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Amazing how smart you can be and still know nothing.
8.33 lbs./gal. x 60 min./hr. x 20°ΔT = 10,000 BTU's/hour

Two btu per sq ft for degree difference for a slab
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Amazing how smart you can be and still know nothing.

Welcome to my world. The percentage of oxygen in the air is the same at high altitude. There is however much less air.

Analyzers read 20.9 at 11,000' just like sea level.
"If you can't explain it simply, you don't understand it well enough"
Albert Einstein
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Hello, Isn't the problem in the article just that they didn't explain their metrics? At sea level you get 100% of that 20.9%. On top of Everest, you get only 33% of that same 20.9%. Otherwise at sea level, with their 100%, it would be way to easy to literally set the world on fire Methinks that article needed a better editor.

Yours, Larry
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It's pretty amazing how our analyzers are all reading the same percentage. Well calibrated (to the atmosphere). The pie chart also explains why compressed Nitrogen is the cheapest gas, and the comparatively high cost of CO2.

I always learn something here at HH! You guys are the best.
Serving Northern Maine HVAC & Controls. I burn wood, it smells good!
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That is a good check, if it read anything else maybe you need a calibration. Know your tools!
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I tried to stick my old EUI in an oxygen rich environment and it would not read higher than 20.9. I think it was programmed that way. Have not tried the Testo 320.
"If you can't explain it simply, you don't understand it well enough"
Albert Einstein
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My Testo 320 reads 20.9 as long as the sensor is good.
Steve Minnich