How do I calibrate a digital thermometer/hydrometer??

[Sue S]

I looked online & can't find info on how to calibrate, I know it's something with salt & a zip lock bag??
I just starting incubating on day 2 & I have a Little Giant still air incubator it has the temp/humidity display panel on it, I put in the digital thermometer/hydrometer I have & both are reading the same for the humidity but not the same for the temp, it's off by about 5 degrees. I'm not sure which is reading incorrectly, my temp/hydrometer is old so it might need calibrated.

 

[SunHwaKwon]

I looked online & can't find info on how to calibrate, I know it's something with salt & a zip lock bag??
I just starting incubating on day 2 & I have a Little Giant still air incubator it has the temp/humidity display panel on it, I put in the digital thermometer/hydrometer I have & both are reading the same for the humidity but not the same for the temp, it's off by about 5 degrees. I'm not sure which is reading incorrectly, my temp/hydrometer is old so it might need calibrated.

A lot aren't able to be calibrated. You have to check it against a food/medical/aquarium thermometer that you can check with ice and a bit of water and then mentally make the adjustment.