I was wondering if anyone who uses one of those machines could tell me what the black spot means next to the S/T icon. It doesn't appear all the time whilst my dad is on it but sometimes when he inhales the black spot is there.
Thank you in advance.
I was wondering if anyone who uses one of those machines could tell me what the black spot means next to the S/T icon. It doesn't appear all the time whilst my dad is on it but sometimes when he inhales the black spot is there.
Thank you in advance.