I have sprayed water on my unit simulating light rain with no adverse effect.
Below is a quote from the user manual:
"Notes for touch control
• A large amount of water drops on the screen can cause misoperation and slow touch
response. Wipe the screen with a dry cloth to remove the water.
• This equipment uses a capacitive touch screen. Tap the screen with your fingertips
directly. Do not use sharp objects (needle, pen, nail) or a stylus pen. Be careful not
to scratch the screen."