| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To achieve a thermal flowmeter for measuring a flow rate over a wide range of measurements. <P>SOLUTION: The thermal flowmeter for controlling the temperature of a liquid flowing in a flow path and measuring a flow rate, based on the temperature difference of a fluid between the upstream side and the downstream side in a temperature control section, includes: the flow path, formed with a wetted section entirely made of glass; a heat transfer means provided on the flow path; a first temperature difference detecting means provided on the flow path and spaced equidistant from the heat transfer means; a second temperature difference detecting means provided on the flow path and spaced equidistant from the heat transfer means, outside the first temperature difference detecting means; and a calculation control means for controlling the temperature of the liquid flowing in the flow path by use of the heat transfer means, selecting the first or second temperature difference detecting means, in response to the measured flow rate, and obtaining the flow rate, based on the detected temperature difference. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
