| 摘要 |
PURPOSE: A mass flow controller is provided to increase a linear flow range of a mass flow-measuring sensor, improve the measuring accuracy and the measuring precision of the mass flow controller, and secure stability of a system. CONSTITUTION: A mass flow controller comprises a passage(110) making a fluid flow; a sample flow tube(221) installed to make the sample fluid always extracted from the passage at a regular rate; a heating unit(222) wound around a predetermined area of the central part of the outer surface of the sample flow tube, to heat the sample fluid flowing in the sample flow tube; a first temperature-sensing unit(223) to sense the temperature of the upper stream of the sample fluid; a second temperature-sensing unit(224) to sense the temperature of the lower stream of the sample fluid; and a heating-unit control part(270) supplying power and controlling power supply, to make the heating unit maintain uniform temperature.
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