In the receiving dock of the pilot plant, part of Cruess Hall is a beautiful old, high capacity (600 lbs?) scale. It's free, accessible 24 hours a day, accurate, can fit multiple people and their favorite objects. It reacts slowly, and the readout is analog.
Springs vs. weights
No springs are involved in this type of scale - the scale head has weights that move and balance the weight of the applied load. —Former scale mechanic
Scales with weights are much more accurate than those with springs (used only on very cheap scales). Springs stretch, loose temper, corrode, and have non-linear force curves. Gravity, on the other hand is highly constant. It varies by position on earth (by almost 1%), but at that location it changes extremely little. Weight-based scales use levers so that (for instance) a 1g. internal weight might balance a 1kg. load. "Legal for Trade" means the scale has been certified by the Bureau of Weights and Measures to be accurate within a certain percentage. They usually have a tamper-evident seal.
This would have made a good mystery picture. -KrisFricke
I tried to find the mysterious scale last night to weigh a bag before a flight. It sadly was no where to be found. -RachelRicks