Abstract: A density sensor includes a stationary housing (12) and a reciprocating body (22) with a float (26) attached thereto to provide a buoyant force. The reciprocating body (22) is connected to a piston (32) by a reciprocating rod (34). The piston (32) is operable to move within a bore (30). A second piston (52) is also disposed in the bore (30) and is coupled to the piston (32) by a spring (54). A transducer (44) is disposed at the other end of the bore and is connected to the piston (52) through hydraulic fluid disposed in a hydraulic chamber (56). The spring (54) is functional to remove low frequency components of acceleration from the buoyant force and the hydraulic fluid disposed in the hydraulic chamber (56) is operable to remove high frequency acceleration components from the buoyant force. In this manner, the transducer (44) can be isolated from both high and low frequency acceleration components.