Abstract: A method and apparatus for measuring specific gravity of fluids such as urine. The apparatus includes a housing and a hollow tube mounted in the housing and open at both ends. The housing is adapted for communication with a source of fluid to be introduced into one end of the hollow tube. The housing is also adapted for connection of pressure differential structure to the other end of the hollow tube for causing fluid to flow from the fluid source through the hollow tube. The tube is vibrated with the fluid therein and electronic response means are employed to measure the vibration frequency of the tube and sample therein and compare the measurement with a predetermined reference frequency to determine the specific gravity of the fluid. The forces to vibrate the tube are produced electromagnetically by impressing an alternating current on the tube itself which is located within the field of a magnet.

Abstract: A centrifuge for varied speed operation. The centrifuge includes a stator portion forming a chamber therein and adapted to be positioned on a supporting surface. A rotor portion is rotatably mounted in the chamber of the stator. A drive motor on the stator rotates the rotor at the desired speeds. Sample holders are on the rotor to hold a number of different type of samples. A cover is on the stator and is adapted to be shifted between the open and closed positions. Electrical controls are connected to the drive motor to vary the speed of the rotor to correspond with the speed required for centrifuging the samples being held which may be blood, urine or hematocrit samples and for starting and stopping the centrifuge.