| 摘要 |
PURPOSE:To set the zero point of a measurement output over a wide range by using a smaller number of elements by inputting the output of a bridge circuit to the uninverted input terminals of two operational amplifiers whose inverted input terminals are connected together through a resistance while feeding electricity to the bridge circuit through the resistance, performing amplification and then differential amplification, and outputting a measurement output. CONSTITUTION:SG 1-SG 4 are diffusion type strain gauges and formed on a pressure- sensitive diaphragm and when measurement pressure is applied to the pressure-sensitive diaphragm, the voltage between the connection point of the SG 1 and SG 2 and the connection point of the SG 3 and SG 4, i.e. the output voltage Vin of the strain gauge bridge varies. When the strain gauge bridge output Vin has positive temperature sensitivity, a switch SW 3 is turned on and a switch SW 4 is turned off to select values of R27-R30 and thus give proper negative temperature dependency, so that the positive temperature dependency can be compensated while the zero point of a pressure transducer output V can be set to a specific value. When the output has negative temperature dependency, on the other hand, the switch 3 is turned off and the switch 4 is turned on to select values of R27-R30, so that zero-point temperature characteristics can be compensated and the zero point can be set.
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