A Hematocrit reader, also known as a microhematocrit centrifuge or hematocrit centrifuge, is a specialized laboratory instrument used to determine the hematocrit value of a blood sample. The hematocrit is a measure of the proportion of red blood cells (RBCs) in the total volume of blood.

The Hematocrit reader operates on the principle of centrifugation. It consists of a rotor or chamber that holds capillary tubes containing the blood samples. When the rotor spins at high speed, the centrifugal force causes the RBCs to separate from the plasma and settle at the bottom of the capillary tube