| 摘要 |
In order to obtain a thermal flow meter that can maintain high detection precision of an amount of flow even in the case of accretion by fouling substances, this thermal flow meter (300) has: a semiconductor member (601) provided with a thin film region (603); a heat-emitting body (608) that heats a gas (30) to be measured and is provided to the thin film region (603); a temperature difference detection means that detects the temperature difference in the direction of flow of the gas (30) to be measured in the region that is at the thin film region (603) and is at the upstream side and/or the downstream side of the heat-emitting body (608); a heat capacity calculation means that calculates the heat capacity of the thin film region (603) on the basis of the temperature difference detected by the temperature difference detection means; and a thermal conductivity change estimation means that estimates the amount of change in thermal conductivity of the thin film region (603) on the basis of the heat capacity calculated by the heat capacity calculation means. |
