The Microlife ear thermometer’s calibration is set with a probe cover. So, measurements without a probe cover result in poor measurement accuracy.
In addition, use of the thermometer without a cover can result in transmission of germs. (unacceptable hygiene) Even a small amount of earwax on the probe tip allows bacteria and fungus to grow outside the ear!
Please use a new cover for each measurement.
The probe cover also protects the infrared sensor from earwax, which can destroy the sensor.