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  #11  
Old February 24th, 2019, 04:43 PM
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-50 to +300??? What kind of crazy weather do you get in Vermont?
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  #12  
Old February 25th, 2019, 03:13 PM
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Originally Posted by Bryan Ex View Post
-50 to +300??? What kind of crazy weather do you get in Vermont?
That seems about right for this winter. Seems to go from long-johns to tee-shirts overnight.

Look at the photo of the thermometer (first post). It gives the range on the face of the unit. That's a range of 350 deg F. 1% of 350 deg F is +/- 3.5 deg F. Those are the specs, which can be found at https://www.wika.us/upload/DS_TMTI_80_en_us_16273.pdf Most likely it'll be better than that, but you can never know for sure. Just because you can read it to within 0.1 deg F doesn't mean that it is accurate at the temperature range you're interested in or precise to that degree. Errors are introduced in a lot of ways. In devices such as this it is often the combination of errors in the thermistor used to "sense" the temperature, or the circuitry, or the algorithm to calculate temperature from resistance. The output tends to follow a straight line, but wobbles back and forth across the line a bit. They take the worst case for each of those components and add them together to get the error limits. So a little error in the resistor, some in the circuit, a bit more in the algorithm....total is +/- 1% (worst case, unless you drop it). Could be it is fine to 0.1 deg F. Could be it's off by 3.5 deg F. Truth is probably somewhere between those two.

Your best bet is any type of thermometer to calibrate it within the range you expect to be working at...so boiling pure water (at sea level under standard pressure) and noting the apparent temperature reading of the device and either changing the calibration (not possible with this device it appears) or just factoring in any offset you note. As I said...it's probably fairly close, but easy to check to make sure you didn't get a funky unit.
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Last edited by DrTimPerkins; February 25th, 2019 at 03:26 PM.
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  #13  
Old February 26th, 2019, 10:16 AM
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OK...so the problem with posts like this are that the details keep me awake for hours at night thinking about all the little things that contribute to measurement errors and how to correct them. No way to shut off my brain once it gets started on something like this.

Didn't help that the wind was howling like a banshee most of the night.

So all of you need to just stop asking such interesting questions! Either that or I need to start drinking more.

Can you tell that we're all just waiting for the weather to warm up and the sap to run?

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