I test in a water bath using medical grade thermometer:
https://www.backyardchickens.com/ar...incubator-thermometers-and-hygrometers.73634/
I also test my hygrometers.
https://www.backyardchickens.com/ar...incubator-thermometers-and-hygrometers.73634/
I also test my hygrometers.