A cycle is 12 hours. So you have 2 cycles each day, AM and PM.
The Alpha Trak will give you different numbers. They aren't wrong, they're just different. They're higher, so don't let that freak you out. There is an Alpha Trak spreadsheet around here somewhere that you might consider using. If not, I would make a pretty big notation on your SS when you switch to the AT, just so that folks here understand. Also, I'd put it in red in your signature so that if you post a number, we know what it means. The reason I say this is since most folks use a human meter, which reads lower, we give advice based on that. If we know it's an AT, we'll be able to give better advice.
If none of that makes sense, please say so. I'm only halfway through my morning coffee, so while I'm totally making sense in my head...I might not even be writing real words here yet!