What is what instrument is used to measure mass?

The instrument used to measure mass is called a balance or a scale. A balance typically consists of a beam supported at its center with two pans hung from each end. The mass of an object is determined by comparing it to standard weights placed in one pan until equilibrium is reached. Scales work in a similar way, using weight as a measure of mass by employing a spring or electronic mechanism to determine the force exerted by an object's mass. Mass is typically measured in units such as grams, kilograms, pounds, or ounces.