$Calibrate your mechanical or electronic shipping scales twice a year to avoid overpayment of freight costs. In some cities, you can find a company that can do this by looking in the Yellow Pages under "Scales." Scale servicing generally costs between $60 and $100, a small price to pay if you find your scales are 10% high and you've just shipped 100,000 pounds of freight. If a scale is "light" (say minus 10%), the shipper may save initially, but if the customer discovers the error, he's likely to take his business elswhere.