determining pin weight

when you go to the scales (e.g. CAT truck scales) there will separate scales in a row adjacent to one another. First you weigh the truck by straddling 2 of the scales so your front tires are on one and your rear tires are on the separate adjacent one. This will give you separate weights for the front axle (called 'Steer Axle' on the weight ticket) and the rear axle (called 'Drive Axle on the weight ticket). Now, hook up to your trailer and go back onto the scales so your truck front axle is on the first scale (as before), your truck rear axle is on the second scale (as before) and your trailer axles are both on the third scale. You'll get another weight ticket that will now show the Steer Axle, Drive Axle and Trailer Axles. To get your pin weight take the difference between the Drive axle weights with and without the trailer hooked up. There may also be a difference in the Steer axle weights that you'll have to take into account based on whether the Steer axle weight went up or down with the trailer hooked up vs. not hooked up.
Also, you can do a web search that will give you info on how to do it and show you what a weight ticket looks like.