THERMOMETER HELP! Mercury vs. Digital

[bugglesmommy]

I got a new second incubator. It came with a thermometer on top and a mercury thermometer. This one has a circulating air fan. I am getting it ready for eggs being shipped and I want to be sure about the temp. I put in the mercury thermometer as well as a new digital thermometer. The built in one and mercury one agree at about 99-99.5° but the digital reads 95. That's a big difference so I put in another digital as well, the one I hatched my last eggs on. It agreed with the other digital at 95.

That makes 2 thermometers reading 99.5 and 2 reading 95. What do I believe?!

The last hatch with the second digital thermometer was in my still air incubator so I kept it at 101. I had 17/21 chicks hatch on days 20 and 21.

I don't know what to trust. If I believe the digital and crank up the heat and am wrong, I could cook them. I listen to the mercury but am wrong I would be incubating them at 95.

Help!!!!!!

 

[Mavrik]

I have several digitals and they all read differently, just because it's a digital, doesn't mean it accurate. You would have to check it with a 'standard' (a calibration tool). Most likely you don't have one. If you have thermometer with a remote probe or thermocouple, you can freeze the sensor in an ice cube. When the cube starts melting (ice can be colder than 32°) you should read 32° on your thermometer. Then just do a math correction when reading units that aren't calibrated correctly.