Originally Posted by flyerCO

Yes. They're charging based on weight. Thus they must be certified. Not all states place a sticker on each scale. Here in TX there's one paper certificate on the wall behind the checkin desk. It certifies all the scales at the DL positions at that airport. However other states don't even have that. Others still put one on each scale. Regardless, they're regulated. Most states scales are regulated by same agency as those in grocery stores.