Abstract: An estimation apparatus 1 includes: a correlation index estimation unit 2 configured to receive a variable output by a component 21 as an input, and estimate correlation index information indicating a range that a value of the variable and a correlation can take after a predetermined time, at a normal time; an abnormality degree calculation unit 3 configured to calculate an abnormality degree using the correlation index information; and a causal effect estimation unit 4 configured to estimate a causal effect expressing an index indicating that an abnormality propagates to a variable output by the component 21.

Abstract: A flow rate sensor is disclosed, comprising a flow rate calculation part that calculates a flow rate of a fluid based on an expression using Xd/Xu that satisfies an expression at least in a certain range of the flow rate when an output of a constant temperature control circuit corresponding to an upstream resistor is defined as Vu, an output of a constant temperature control circuit corresponding to a downstream resistor is defined as Vd, and the flow rate is defined as and the flow rate calculation part corrects the zero point output as being an output when the flow rate is zero by using a zero offset function (OFS) defined as a function of Vu+VdXd/Xu.

Abstract: A flow rate sensor is disclosed, comprising a flow rate calculation part that calculates a flow rate of a fluid based on an expression using Xd/Xu that satisfies an expression at least in a certain range of the flow rate when an output of a constant temperature control circuit corresponding to an upstream resistor is defined as Vu, an output of a constant temperature control circuit corresponding to a downstream resistor is defined as Vd, and the flow rate is defined as and the flow rate calculation part corrects the zero point output as being an output when the flow rate is zero by using a zero offset function (OFS) defined as a function of Vu+VdXd/Xu.