PHRM38BK heart rate monitor

wwk10

Just got it today. Very basic, but looks OK. Interface is terrible.
Question:
It says it records High heart rate and average heart rate.
But it looks like this is a lifetime high and a lifetime average.

Is there any way to record the high and the average for a session?

For example, what is my high and average heart rate during a tennis match or during a run?
Thanks