Calibrating thermometers and hygrometers?

[Godiva]

How do you do this, and how do you know if you have one that can be calibrated? I have two combination therm/hygr and they are in disagreement

not sure which one to believe. DH has run out to see if there is a cheap one at Walmart but I would like to learn this so can either replace or fix the one's I have.

 

[leaddog]

If they are disagreeing on temp get a glass, a quart jar is good. Fill with ice and then fill it nearly full with water. It is important to have as much ice mass in the solution as possible. After a few minutes that solution should be at 32 F or 0C. Cubes are OK but crushed is better if you have it. If the sensor is not water proof put it in a surgical glove, baggie, or something really thin and water proof, then imerse in the center of the already cold water solution read and adjust the temp.

UMMMM hygrometer......I will have to check on that...

 

[reereechickens]

For the hygrometer I use a tablespoon of salt in a plastic bag with a zip closure. Then add a few drops of water until it is like spackle thick but not too runny. Put hygrometer in baggie away from the salt mix and seal up and read in 4 hrs. Should read 75%. Some people wait 6 or 8 hrs.

If you get a reading like 72% add 3% to your reading or if you bought a hygrometer for a cigar humidor and can adjust with a screwdriver, do so. I bought mine from ebay.

 

[Godiva]

Thank you so much both of you - awesome information! I have been going crazy trying to figure out what temp is the right one! DH brought a new thermometer/ humidity unit from Walmart and it won't even turn on! How typical is that of my day!