Patent ID: 8527243

Claim:
An air flow measurement apparatus comprising: a signal processing unit comprising: (a) a flow detector including a flow sensor configured to detect air flow through a flow passage, the flow detector configured to convert an output signal of the flow sensor into a voltage; (b) a reference voltage generator configured to output a plurality of reference voltage signals used for a correction applied to a flow voltage signal that is the output signal of the flow sensor; and (c) an A/D converter including a multiplexer configured to sequentially select the flow voltage signal and the plurality of reference voltage signals in a predetermined order, the A/D converter configured to sequentially sample and convert the flow voltage signal and the plurality of reference voltage signals into digital data in the order selected by the multiplexer, wherein the signal processing unit applies a calculation or the correction to the digital data of the flow voltage signal using the digital data of the plurality of reference voltage signals, the signal processing unit including a sampling timing setting section configured to set sampling timings at which the A/D converter samples the flow voltage signal and the plurality of reference voltage signals, and the sampling timing setting section sets the sampling timings in such a manner that the sampling timing at which the air flow voltage signal is sampled is interposed between the sampling timings at which each successive two of the plurality of reference voltage signals are sampled.