I have investigated nearly all the recommendations found in this thread
CAT does discourages the use of their scales for 4-corner weighing
I did extensive Google searches for "Truck Scales"
I finally discovered the secret
Try searching for "Scale Rentals"
To be exact try "Axle Scale Rentals"
You might also try "Scale Calibration"
You will be surprised -- I found a place 2 miles from my home