Here's the actual process that you should go through with getting weighed when pulling a travel trailer. I don't get into digesting the numbers, but there are plenty of forums where you can post, "Hey I weighed, and this is what I got" that will help you out.
Assuming that you're doing it at a CAT scale that has 3 scales that you pull onto:
|CAT Scale Setup (shows a fifth wheel, but a travel trailer is the same)|
- Weighing Truck and Travel Trailer with weight distributing hitch (WDH) hooked up; you want your truck's front tires (aka steer axle) on the first pad; truck's rear tires (aka drive axle) on the second pad; all trailer axles on third pad (see the graphic above)
- Weighing Truck and Travel Trailer without weight distributing hitch hooked up; put the WDH bars into the bed of the truck
- Weighing Truck Only; park the travel trailer in a truck parking spot, put the WDH bars with the travel trailer (locked inside) and come back around to just weigh the truck
Quick update: you'll want to pull off of the scale between weightings #1 and #2 to remove the WDH bars and whatnot. It'll keep you from holding up the line and confusing the scale master.
Important Notes for WeighingThroughout all 3 weighs, nothing should change - no moving of passengers, no one goes to the bathroom, etc. Do them all at once (not before and after a trip, for instance).
As well to get as realistic numbers as possible, you want to be packed like you were ready to go camping on your average trip (weekend, week, month - whatever is normal for you). If you don't have all of your passengers, you'll have to add their weight when you evaluate your results.