Measurements of flow velocity in a microscopic region using a transmission grating: a practical velocimeter

Abstract

This paper reports a practical differential-type transmission-grating velocimeter system for measuring the flow velocity in a microscopic region. This practical velocimeter is constructed with a useful optical system and an improved signal-analyzing system; it is used for measurements of the flow velocity in a biological field. The velocimeter also measures moving rough surfaces in a small probe area. The experimental results show the applicability of the transmission-grating velocimeter to measurements of blood flow velocity and to the velocities of various moving rough surfaces in a microscopic region.