Measuring slow pulses

[uhrheber]

Hi.

I want to measure the rpm of the wood pellets spindle in my oven. The spindle turns very slowly, about 1 rpm. As I want to be aware of congestion problems that lead to a (too) slow turning spindle, I want to be able to not only count the pulses, but also measure the time between two pulse, to get an early warning when something is wrong.
Is this possible somehow?
Maybe by triggering an event at every single pulse, and calculating the system time difference between them?

Thanks
Uhrheber