| 摘要 |
PURPOSE: A transducer of the attachment for ventilating is provided to correct the error of the measured value according to changing of the temperature by measuring low speed and flowing and by introducing micro processing technique CONSTITUTION: A transducer of the attachment for ventilating includes a regulator circuit(1), a constant current circuit(2), an amplifying circuit(3), a thermistor(4), an A/D convertor(5), an offset and gain controlling circuit(6), a MICOM(7), a memory circuit(8), a pressure setting circuit(9), a relay circuit(10) and a 4-20mA output circuit(11). The regulator circuit(1) generates the voltage for the transducer 24 VDC output and the circuit driving constant voltage. The constant current circuit(2) generates the constant current of 1mA. The amplifying circuit(3) makes the output from the pressing sensor the full range of the A/D converter. The thermistor(4) measures and corrects the temperature. The A/D convertor(5) converts the analog output of the temperature sensor and the pressure sensor into digital and conveys it to the MICOM(7). The offset and gain controlling circuit(6) includes the offset variable resistance controlling the output as 4mA in 0 of the sensor and the gain variable resistance controlling the output as 20mA in the full scale. The MICOM(7) generates correcting the temperature and the output. The memory circuit(8) memorizes the offset value and the span value in the high temperature of each pressing sensor. The pressure setting circuit(9) sets up the pressing value to generate the relay output. The relay circuit(10) generates the relay contact point signal. The 4-20mA output circuit(11) generates the output of 24V and 4-20mA.
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