Checking my thermometer.

[geareduplyn]

I have an old bent stem Weksler Mecury thermometer with an 8" probe. It was calibrated in a lab years ago and the 99.5 setting was etched in the glass. It's the only one I trust. I set all my new digitals to whatever they read when it is at 99.5. It must work because all my chicks pop out at exactly 21 days. I really like the new thermometers because they are so much easier to read, but if you can find a good mecury one, get it calibrated and use it as a master.

 

[sandspoultry]

Quote:
You have quoted a 185 degree span in temp. I was talking about 68 degrees. there is a big diff there. Is your fluke calibrated? Water starts to boil at 212 at sea level and the boiling point changes with elevation. yes? And price means quality and has every thing to do with a quality instrument.

Steve in NC

 

[rebelcowboysnb]

Quote:
Its calibrated to 0*. And I know air pressure changes the boiling point of water. The higher up you are the lower the boiling point. So if I factor that in then it drifts even more. How would you figure drift without measuring at two known points an doing the math?

The argument that your thermometer is write because it cost a lot don't fly.
Here, from Consumer Reports.
"We verified the accuracy of a glass oral thermometer and used it to compare against the ones we tested"

"Price and performance don't necessarily correlate. Extrapolating from our recent tests of oral, ear, and forehead thermometers in 24 adults and 21 children ages 5 to 14, we found you don't always get what you pay for. Thermometers can be pricey, but the best cost less than $15."


A glass mecury thermometer premarked would be nice to have too.

 

[shelleyd2008]

Quote:
This is the most accurate way to calibrate a thermometer. Even with boiling water, it is not as accurate. Depending on the altitude where you live, as well as other factors associated with the weather, water does not necessarily boil at the same point.

 

[sandspoultry]

Quote:
Its calibrated to 0*. And I know air pressure changes the boiling point of water. The higher up you are the lower the boiling point. So if I factor that in then it drifts even more. How would you figure drift without measuring at two known points an doing the math?

The argument that your thermometer is write because it cost a lot don't fly.
Here, from Consumer Reports.
"We verified the accuracy of a glass oral thermometer and used it to compare against the ones we tested"

"Price and performance don't necessarily correlate. Extrapolating from our recent tests of oral, ear, and forehead thermometers in 24 adults and 21 children ages 5 to 14, we found you don't always get what you pay for. Thermometers can be pricey, but the best cost less than $15."


A glass mecury thermometer premarked would be nice to have too.

The two known points are known as the span or range. When you take a span of 185 degrees from 32 to 212 your error is greater. when you check your thermometer as I sugested your range is from 32 to 100 degrees you are talking 68 degrees, the smaller the range the less the error. From being in the HVAC biz and calibrations on sensors in the field I have a knoweldge of the process for the last 20 ish years. I am also certified to do field calibrations and do so on a day in and day out basis. The quickest way to field check a sensor is the ice water bath if you don't have a calibrated standard. Have a nice day

Steve in NC

 

[rebelcowboysnb]

I've got certifications for home an auto AC repair an have been doing it sence high school, it don't make me more or less right than someone playing in there basement. I also calibrated those censers with ice water but the only thing that proves is that it is accurate at 32*. Any assumptions I would make of there accuracy at 100* would be just that, an assumption. It may be perfect but I don't know. So I would rather prove accuracy at 100*. I mean were talking about a difference of something like .8* so odiously I'm picky. If I can check it to a known temp close to 100* then I don't have to make any assumptions. An now that I've checked my oral thermometer on 8 people and it matched the one in the ambulance, in my mind I've proven its accuracy.