| 摘要 |
A thermal flow meter has a sensor chip, a heater, first and second flow rate calculators, and an output controller. The heater increases the ambient temperature in the vicinity of a pair of temperature-sensing elements on the sensor chip by a particular temperature above a temperature of a fluid flowing along the sensor chip. The first flow rate calculator calculates a flow rate of the fluid from a temperature difference detected by the pair of temperature-sensing elements. The second flow rate calculator calculates a flow rate of the fluid from a driving energy of the heater. The output controller outputs the flow rate calculated by the second flow rate calculator, instead of the flow rate calculated by the first flow rate calculator, when the flow rate calculated by the first flow rate calculator exceeds a flow rate threshold value that is set in advance. |
