Adept Makine
Accurate humidity measurement is one of the cornerstones of successful incubation. Cheap thermometers can drift over time; calibrate with the salt test at least once a year.
For the salt test, place a salt-and-water mixture in a sealed container; after 24 hours the hygrometer should read 75% (±3%). If it reads differently, note the offset and add/subtract from your readings.
Factory-calibrated sensors in INCUVIONLAB machines make this step unnecessary; however, keeping a spare hygrometer is always a good habit.