Ultrasonic flow meter having protection joint interposed between the measurement unit and the external pipe

A straight tube ultrasonic flow meter comprising a measuring unit disposed within a measurement space of a casing, the measuring unit comprising a tubular body for measurement as a straight tube through which a fluid for measurement flows and a pair of oscillators disposed around an outer circumference of the tubular body for measurement at a predetermined interval along an axial direction, the measuring unit measuring a flow rate of the fluid by obtaining a flow velocity of the fluid for measurement based on a difference in propagation time of ultrasonic waves from both directions detected between the oscillators,

• wherein the straight tube ultrasonic flow meter further comprises a measuring unit protecting joint which is interposed between the measuring unit, the casing and an external pipe,
• wherein the measuring unit protecting joint has a protecting joint main body;
• wherein the protecting joint main body includes a pipe supporting section in which the tubular body for measurement is inserted to a predetermined position,
• wherein the tubular body for measurement and the external pipe are connected to form a fluid channel at the pipe supporting section, and
• wherein the measuring unit protecting joint restricts movement of the tubular body for measurement of the measuring unit in the axial direction and rotation of the measuring unit with respect to the casing through the pipe supporting section.