Yup pretty routine.
Basic when you get scanned, regardless of the actual type of scanner, one of three things happen...
1. No alarm and you go about your day.
2. The machine randomly pings. You get swabbed and, provided you pass this off you go.
3. The machine pings because it actually detects something, ie a belt

, you get searched and swabbed and as above.
The swab is a counter terrorist explosives check and contact with an airbag can set it off (to give an idea of sensitivity), and to be compliant the scanners HAVE to throw out random passengers for swabbing. Same applies to your bags, (both checked and carry).
A full alarm means a full pat down etc, and officially they should also pull your bag and search it. They get really pissed off when you pull them up for not doing this, but they leave themselves wide open by not doing it

The body scanner picks up everything down to tissue in pockets so some airports make you remove your belt so they have less chance of having to search you, on part for time saving and in part complacency. I generally refuse to remove my belt going through the Heathrow scanners... They don't like it, but if you make a point of statement that you aren't refusing a search, they can't do much about it.
The liquid limits for crew are, how to put this..., variable, but the scanner and swab process is universally applied.