It all comes down to the the accuracy and precision of the scales (load cells) you're using.
A high quality scale might have an accuracy of +/- .1%. If it's intended for a 5000lb race car, that would be +/- 5lb.
Sailors love to talk about weighing boats, ... sm
Agree, NIST for commercial use is 0.1%, 5 lb per 5,000 lb. I bought a 5,000 lb load cell to weigh multihulls on a crane for ratings. The load cell was certified again last year at Acme Scale / San Leandro. Fortunately, a local IRC measurer gave me a hint on what to ask for.
Acme Scale explained it to me. The commercial certification is to 0.1% with offsets or corrections at 1,000 lb (+2lb) 2000 lb (+1lb) ... 5,000 lb -3 lb.
An automobile (or small truck) scale is ~OK for larger multihulls ( > 24 feet).
10,000 * 0.001 = 10 ~ok
300,000*0.001 = 300 not ok
The ISAF ERS gives some guidance on weighing boats. The F18 fellows weigh more boats than most, hats off. The texel/schrs outputs are sensitive to the sailing weight inputs. Weighing a boat consumes time many sailors prefer to spend on the water.
