This article goes into detail on how to calibrate thermometers, at the end it explains how to salt test a hygrometer.I ordered 2 off Amazon as wellthose are what is reading so low. However not sure how much sense it makes cause our room is at 30. What is salt test?
https://www.backyardchickens.com/ar...incubator-thermometers-and-hygrometers.73634/