Heart rate monitor : continuous monitoring

Hi,

I noticed that the heart rate monitor seems to work continuously. I have set it on "auto" but I tought it would monior for exemple each hour or each half an hour but mine seems to monitor all the time or just stop when I am not moving but as soon as I move, it seems it is measuring.

I am affraid the sensor will be damaged xhen monitoring all time and that battery life will be significantly reduced.

Is this behaviour normal ? Is it possible to have juste some times per day monitoring ?

Thanks