A weighing scale is a device used to measure a person's weight and is one of the most commonly used devices by doctors. There are two types of weighing scales: mechanical weighing scales and digital weighing scales. The mechanical scale has a revolving dial that displays the weight. Weighing scales and balances calculate weight by measuring the force applied to the load cell. They next convert the result to mass and present it in a variety of mass units. The outcome would be measured in Newtons if they did not convert it to kg or pounds. Gravity affects the outcome of scales.