How Are Scales & Balances Built?
Sensors A special sensor called a ceramic variable capacitance load cell is built in to high quality balances and scales for accurate weighing. The ceramic variable capacitance load cell is fused together with a pair of gold enameled bars. The gold bars are electrodes, which are separated by a very small breach (roughly .003 inches apart). An oscillator circuit is wired to the ends of the electrodes. The load cell has a spring that sends an electrical signal in response to the pressure (downward movement) of the scale pan. When an object is placed in the scale pan, the pan presses down on the spring. Scales and Balancers A scale pan is centered in the fixture of the scale or balance device. This scaling pan receives a load by the operator to measure. The weight of the load on the pan causes a pair of ceramic rods to bend, which then disrupts the breach between the golden bar electrodes. The capacitance between the golden bar electrodes changes with the movement of the gap between them.
