[Test-Equipment] "Event logging" T & M equipment?

[Dave C]

Data logging devices are commonplace now days. Many high-end multimeters have such a feature where you can plug the meter up to a power source and record levels over time. 

But I'm interested in recording out-of-bounds events such as spikes and sags in mains supply. 

This type of measurement is typically only found in power systems analyzers which are quite "$pendy". 

Anybody know of an event logger that is affordable?

THanks,
Dave