| 摘要 |
The flow amount measuring apparatus has two detecting portions for generating signal indicative of flow amount respectively. The outputs of two detecting portions are subject to a differential amplification and outputted. As a result, it is possible to obtain large output. Large output enables lowering of an amplitude ratio of an amplifier portion. As a result, adjusting the amplifier portion becomes easy. A plurality of resistors providing the detecting portion may be formed on a single substrate by the same manufacturing process. As a result, it is possible to reduce errors of the resistors. In addition, the flow amount measuring apparatus may be constructed so that gain and offset of the amplifier portion are adjustable. The output characteristic of the flow amount measuring apparatus can be adjusted by adjusting the gain and the offset. The offset may include a first offset component which varies depending upon temperature of fluid as detection object and a second offset component which is constant and not dependent upon temperature. The first offset component varies in accordance with temperature of fluid so as to reduce temperature dependency of the output characteristic. As a result, it is possible to perform an accurate flow amount measuring.
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