Newbie Question - thermometers

[chicksntexas]

For all of you experienced chicken peeps....I have a Little Giant incubator with fan & auto egg turner. 2 glass thermometers and 1 digital hygro-thermometer. Bator has been running for about 15 hours. The glass thermometers show 100 and the hygro shows 98.8 (& 51% humidity)
Question is....which thermometer should I trust???

 

[Ridgerunner]

Which one have you calibrated?

Rebel’s Thermometer Calibration
http://cmfarm.us/ThermometerCalibration.html

Rebel’s Hygrometer Calibration
http://cmfarm.us/HygrometerCalibration.html

I'll probably be as clear as mud this morning, but I'll try. Due to manufacturing tolerances, not all thermometers read the correct temperature. If you go to a place that sells a lot of thermometers for measuring outside temperatures, you can often see several degrees difference in what they are reading even in a climate controlled building and on the same shelf. I've seen as much as 9 degrees Fahrenheit difference on the high and low on the same shelf with the same model of thermometer. That is one issue that can be handled by calibration.

There is another issue. Not all thermometers are designed to be real accurate. This is about repeatability, not reading the correct temperature. Many of those thermometers used to measure temperature outside are designed for a repeatability of 1 or even 2 degrees Fahrenheit. This means that if the temperature is 80 degrees outside, that thermonmeter may read 78 degrees. Then, after a cycle of heating or cooling and it gets back to 80 degrees, it might read 81 degrees. Most are better than this, but some are not much better. You cannot handle repeatability by calibration. What you need for incubation is to find a thermometer that is accurate to within 0.1 degrees C or F does not matter) then calibrate it.

Hope this helps. Good luck!

 

[chicksntexas]

Thanks ! I calibrated the glass thermometers...and one was exact! yay! The other one was off a couple of points. I'm calibrating the hygro now...thanks for the info!