| 摘要 |
<p>PROBLEM TO BE SOLVED: To further downsize a thermal type gas flowmeter and reduce a manufacturing cost thereof and highly accurately detect a flow rate at all times even if a gas temperature fluctuates.SOLUTION: A gas flowmeter is constituted of a sensor part A which is arranged in an upper part of a sensor part storage body 4 having a fluid passage 11, horizontally hung and supported by a fixing terminal rod 16 inside the fluid passage 11 and includes: a thermistor temperature detector 22 for a gas temperature detection before being heated; a thermistor temperature detector 23 for a gas temperature detection after being heated; a heater element 24; and a flexible circuit board 15 provided with a shield plate 18, and a CPU flow rate control circuit board 6 for calculating the gas flow rate on the basis of each temperature detection from the sensor part A. Holding a temperature difference between both the thermistor temperature detectors 22, 23 at a predetermined set value by adjusting an input voltage V to the heater element 24 allows the gas flow rate to be calculated from the value of the input voltage V.</p> |
