So recently the Stockton Fire Department shared a post on Facebook about a fire in the Downtown area. When they were entering the apartment building, at the 31 second mark, you can hear the fire alarm notification device.
The thing is, it is not March Time, Code 3, nor is it slow whoop.
Here’s the video from YouTube from Stockton Fire. Any idea what the temporal pattern is and possibly the make? https://www.youtube.com/watch?v=DJRqsv0zelI
That’s not temporal at all, that’s a multi-tone sounder or sounder/strobe in continuous doing a hi-lo tone. Almost kinda sounds like a European fire sounder, though it probably isn’t as such devices aren’t really seen or used in North America (if at all). It kinda sounds like a System Sensor MASS on hi-lo: System Sensor MASS: 800-1000Hz Alternating (Hi-Lo) - YouTube but it’s a little fast for a MASS.
It could be a MASS but I suspect it is a UK sounder.
Turns out that it probably is a MASS due to what looks like a MASS appearing very briefly at 0:43 above the entrance door.
thank you for clarifying that the alarm is a MASS. I was able to pause the video just right to see the actual notification device (split second on the dot 43 second mark). I had only seen the the fire panel on the wall originally.
You are quite welcome. 
That’s probably not the only MASS in the building I’d imagine, though what’s weird is that the one above the entrance door doesn’t appear to be emitting any sound (or at least it sounds like it isn’t).