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AC_Hacker · 04-30-13, 12:22 PM

"E=Fornax;29680]Although the 10 thermometers do agree with eachother the actual temperature measured with 2 known-good ones (also visible in the images) is a full 2 degrees centigrade lower...[/QUOTE]

I think your results are amazingly consistent.

If I'm not mistaken, these thermometers use 1-wire sensors which are advertised to be within 1/10th degree C, so it looks like your thermometers are pretty close to that.

You might try the same setup at different temperatures, to see how well they track. Use boiling water (100 C) and ice (0 C) as extreme points.

BTW, I have been doing some experimenting with a high quality Temp/Humidity sensor, and I am quite pleased with it's results.

In my heat pump work, I have become very disenchanted with 'digital'. I now know that it just means 'numbers, and not necessarily accuracy, unless forced to be accurate. Don't be fooled by decimals, they aren't a sign of accuracy, they are a sign of decimals.

I have tried a very large array of temperature measurement tools... cheap thrift store digital thermometers, non-contact infra-red, alcohol column, mercury column, bi-metallic, analog electronic (thermistor, lm-135, thermocouple), digital electronic (1-wire).

But when everything seems to no longer make sense, I have one lab-grade mercury column sling psychrometer that has two columns and even though it will not give me resolution to 1/10 degree, I really trust it.

I think that your selection process is really a good approach... but, be careful, you might become a scientist.

Best,

-AC

04-30-13, 12:22 PM	#2
AC_Hacker Supreme EcoRenovator Join Date: Mar 2009 Location: Portland, OR Posts: 4,004 Thanks: 303 Thanked 723 Times in 534 Posts	"E=Fornax;29680]Although the 10 thermometers do agree with eachother the actual temperature measured with 2 known-good ones (also visible in the images) is a full 2 degrees centigrade lower...[/QUOTE] I think your results are amazingly consistent. If I'm not mistaken, these thermometers use 1-wire sensors which are advertised to be within 1/10th degree C, so it looks like your thermometers are pretty close to that. You might try the same setup at different temperatures, to see how well they track. Use boiling water (100 C) and ice (0 C) as extreme points. BTW, I have been doing some experimenting with a high quality Temp/Humidity sensor, and I am quite pleased with it's results. In my heat pump work, I have become very disenchanted with 'digital'. I now know that it just means 'numbers, and not necessarily accuracy, unless forced to be accurate. Don't be fooled by decimals, they aren't a sign of accuracy, they are a sign of decimals. I have tried a very large array of temperature measurement tools... cheap thrift store digital thermometers, non-contact infra-red, alcohol column, mercury column, bi-metallic, analog electronic (thermistor, lm-135, thermocouple), digital electronic (1-wire). But when everything seems to no longer make sense, I have one lab-grade mercury column sling psychrometer that has two columns and even though it will not give me resolution to 1/10 degree, I really trust it. I think that your selection process is really a good approach... but, be careful, you might become a scientist. Best, -AC __________________ I'm not an HVAC technician. In fact, I'm barely even a hacker... Last edited by AC_Hacker; 04-30-13 at 12:24 PM..