Gotta disagree with you.
Yes, you need accuracy better than 20%; this is why. The Devil is and always has been in the details. 2 temperature points do not, and have never told the story in any exo-thermic device. They tell what is happening at 2 points in space - and only when you are looking at them.
Thermocouples tell you what is going on - constantly and very accurately. They are cheap, and intentionally have insifignicant thermal mass. This is why jet engines have more than 2 temperature points - and this is every bit as complex as a typical jet engine. Heck, your car uses more probes and far more accurate probes than what this is using. Input air temp, water temp, manifold temp, transmission temp, exhaust manifold temp, exhaust temp, ambient temp, brake temp and that’s just off the top of my head. My car had 5 oxygen sensors on top of this.
Depending upon what you are measuring, and when; this could be returning more heat than is put in, or LESS. This is apparent in the LERN-CANR.org website.
“Unfortunately, this test was marred by problems that make it impossible to accurately determine how much energy was produced”.
Not my quote - this is from LENR-CANR.org. I suggest you read the article (www.lenr-canr.org/News.htm) yourself. We do not know how much energy this unit is actually producing. That’s a hell of a condemnation on the measurement strategy used.
Again...”Experts from Motorola and elsewhere have analyzed the data. Most of them have concluded that the excess heat was real, and anomalous” - so it appears something cool is happening; but we don’t know how much because we have sh*tty instrumentation.
I've read it. I've also read the reports of the experiments/demos themselves. And as a result of that, I disagree with the conclusion. I repeat, Rossi's rigs can be completely characterized with two thermometers, a barometer, and a beaker.
And I suggest, as i always do, that you need to read the actual reports, and not the commentaries thereon. You say you know something about measurement.....check the facts, not the opinions.