1. When the device is powered off, press and hold the measurement button for 8 seconds to enter unit switching mode. Under this mode, both Fahrenheit and Celsius should flash at the same time.
  2. Under this mode, press the measurement button to switch to Fahrenheit or Celsius. The corresponding symbol of the selected unit after switching will flash.
  3. After selecting the unit, press and hold the measurement button for 8 seconds to leave the unit switching mode.