Spring scale 弹簧秤
(重定向自Spring balance)
A spring scale or spring balance is a type of weighing scale. It consists of spring fixed at one end with a hook to attach an object at the other. It works by Hooke's Law, which states that the force needed to extend a spring is proportional to the distance that spring is extended from its rest position. Therefore the scale markings on the spring balance are equally spaced. A spring scale can not measure mass, only weight.