Do not forget to warm the harmonica in your hands before you start playing.
Warm breath into a cold harmonica will result in a lot of humidity in the air channels and on the reed plates, which may cause several problems.
Any moisture on the reeds will lower the pitch.
The moisture can also make the flaps stick to the plate. Additionally, the double flaps systems are prone to adhesion between flaps, which may disturb the function of the flaps even more.
Consequently, never blow into a cold harmonica!
The Polle LCT sensor
A liquid crystal temperature (LCT) sensor is integrated into the body of a Polle harmonica, next to the slide button. The LCT sensor operates without batteries.
The Polle LCT sensor helps the performer to identify the optimal temperature of the instrument. As the instrument is getting warmer, a numeric temperature indicator will emerge on the black surface. The indicated temperature (℃) has been reached when the number turns green.