A spring scale measures weight by the distance a spring deflects under its load. A balance compares the torque on the arm due to the sample weight to the torque on the arm due to standard reference weight using a horizontal lever. Balances are different from scales, in that a balance measures mass (or more specifically gravitational mass), whereas a scale measures weight (or more specifically, either the tension or compression force of constraint provided by the scale). Weighing scales are used in many industrial and commercial applications, and products from feathers to loaded tractor-trailers are sold by weight. Specialized medical scales and bathroom scales are used to measure the body weight of human beings.
Balances and scales are available for application needs of the hospitality, retail and industrial fields, ranging from analytical balances to compact balances to industrial benchtop scales and platform scales.