To followup one more step from what myredracer poated, here is the step by step that Ron wrote up for us several years ago:
The procedure is applicable for a 3-pad scales.
If you want to use the scales data to determine tongue weight, and if you want to get the maximum information about your TV/TT combination and how well your weight distrtibution system is working, you need data from three weighings. Second and third weighings usually are done at a lower cost.
And, you need to find a scales with at least three separate weighing platforms so you can separately measure all three axle loads at the same time. Most, perhaps all, CAT scales have this feature.
If you need any help in interpreting the scales results, just post the numbers. There are several ORF members who can help with the calculations.
First, the TV and TT should be loaded approximately as they would be for camping.
Second, the weight distribution system should be adjusted as it normally would be for towing.
Then, I would do the following:
Weighing #1 -- TT attached and Weight Distribution Activated
Let Front Axle Load be "FA1"
Let Rear Axle Load be "RA1"
Let TT Axles Load be "TT1"
Then, remaining in same position on scales, take
Weighing #2 -- TT attached and Weight Distribution Not Activated (WD bars unloaded, but hanging in place) -- ask the operator for a "re-weigh":
Let Front Axle Load be "FA2"
Let Rear Axle Load be "RA2"
Let TT Axles Load be "TT2"
Then, drive off scales and drop TT. Return to scales and take
Weighing #3 -- TV only -- TT Not Attached -- ask operator for another re-weigh:
Let Front Axle Load be "FA3"
Let Rear Axle Load be "RA3"
From the above values, you can calculate:
TV weight = FA3 + RA3
Gross Combined Weight = (FA1 + RA1 + TT1)
{should also be equal to (FA2 + RA2 + TT2) if scale weights are correct}
TT Weight = Gross Combined Weight - TV Weight
Tongue Weight = (FA2 + RA2) - (FA3 + RA3)
Load Transferred to TT Axles
when WD System is Activated = TT1 - TT2
This procedure should get you on and off the scales fairly quickly and still provide all the data you need.
Ron
