Dear @simon,
The actor I would use in this situation is "Compare Guarded." You specify a range within which nothing happens; if it goes above or below this range, you'll get a trigger.
In your case, I'd set 'low' to 53 and 'high' to 60 or something like that.
The smoother is also helpful to get rid of the jitter, but will also (by its nature) introduce some amount of delay.
Best,
Mark