Before electronic scales were invented, our grandparents used mechanical scales and balances. A scale is an instrument that works by moving a pointer with a spring (some kitchen scales or personal scales that work this way are still available), and a balance is an instrument with two standard weight pans (you may have seen them in museums or old drugstores some). These days, the two words are used interchangeably for modern digital instruments.

A balance or scale is defined by two characteristics: capacity and accuracy. Capacity is the approximate maximum weight the balance can measure (such as 600 grams or 5 kilograms), and accuracy is the smallest increment it can distinguish and display. For example, milligram balances can read up to 0.001 grams. The less accurate the balance, the more expensive it is. Milligram balances with a capacity of 200 grams are much more expensive than 200-gram (0.01 gram) balances.

When you choose to buy some scales, keep the following in mind:

Mode of Operation: Most precision and laboratory scales operate on batteries and an AC adapter. Kitchen scales are usually battery-powered only. These battery scales have an automatic shut-off feature to conserve battery power. On some scales, this auto-off mode can be disabled. Beware of buying products that can disable the auto-shutoff feature.

Geometry and Material: When choosing a balance, keep in mind that it will inevitably spill. Choose a pan that is easy to clean and not prone to corrosion.

Placement: Place your scale on a sturdy table or counter. The more accurate the balance, the more sensitive it is to vibrations. For example, analytical balances (accuracy from 0.001 g) should be placed on special balance platforms with granite work surfaces in order to work without any hindrance. You don't necessarily need any granite surface, but take care to keep the balance in a fixed location away from direct sunlight, electrical noise, and vibration. The smaller the scale's displacement, the more precisely it functions.

Xiangshan Zhengtai Electrical Appliance Co., Ltd. is a mechanical scale manufacturer from China. The company designs, processes, and sells personal care scale, bathroom electronic scales, and other electronic scale products.