The Ohaus 1550-SD Harvard Trip balance features a two-pan design based on the classic Roberval balance principle, with the additional advantages of magnetic damping, beams with sliding weights, and a variety of weighing platforms. Commonly used for comparative weighing to determine the difference in mass between two objects, rather than their absolute value, the 1550SD balance comes equipped with built-in sliding masses. This series of balances features accuracy and durability