What is a word for the state of being instantaneous or sustained? For example, with *minimum* or *maximum*, a good choice might be [*bound*](https://english.stackexchange.com/a/34814/58563).

As far as the context goes, I'm working on adding some logging in to some software, and it'll keep an eye on certain statistics and see if they rise above or drop below certain thresholds. One of the ways it'll be configurable is in whether each statistic will trigger a logging statement if its *current value* steps out of bounds *sustainably* ("Sustained"), whether its *average value* does so *sustainably* ("Sustained Average"), or whether its *current value* just does so *at all* ("Instantaneous"). So I'm thinking about what to call this configuration.