| 摘要 |
A thermal type flowmeter (101) includes a sensor element (10), an output circuit (11), a storage unit (20), and an abnormality determination unit (22). The sensor element (10) includes an upstream-side thermopile (1), a heater (2), and a downstream-side thermopile (3). The output circuit (11) outputs a signal expressing a flow rate of a fluid based on a difference voltage between an output voltage (Vu) of the upstream-side thermopile (1) and an output voltage (Vd) of the downstream-side thermopile (3). A referential relationship, in which a reference of a relationship between the voltages (Vu and Vd) is defined, is previously stored in the storage unit (20). The abnormality determination unit (22) compares the relationship between the voltage (Vu) output from the upstream-side thermopile (1) and the voltage (Vd) output from the downstream-side thermopile (3) to the referential relationship, and determines abnormalities of the upstream-side thermopile (1) and the downstream-side thermopile (3). |
