I take a small plastic stool with me to the CAT scales so I can reach the attendant button. Also, remember to ask them to give you a minute to get back in the truck so your weight will be included. Lastly, take note where your tires are positioned when you do multiple weighs and try to pull up to the same place. It drove me crazy when I used to do the triple weighs for a travel trailer first "with" and then "without" the WDH engaged.
The Total Ticket weight would sometimes be 20 to 40 pounds off and the only difference between the two weighs was on one I had the WDH attached and operational and on the other one, I had it loose and not engaged. No I didn't remove any of the parts.
I expected the Total Ticket weight for both should be the same and all that should have been different would be the amounts on various axles. Whe I asked CAT, they said their is a small percentage of accuracy that can varie between weighs.