| 摘要 |
PURPOSE:To perform approximate correction on a measured flow rate of a fluid without receiving any influences of the change in the temperature and pressure of the fluid, by multiplying the volume flow rate under a designed standard condition by a correction coefficient corresponding to the measured absolute temperature of the fluid together with the temperature and pressure correction terms and performing moisture correction. CONSTITUTION:An absolute moisture detector 5, such as zirconia type hygrometer, etc., and the 2nd arithmetic means 7 are installed to a measuring instrument composed of a differential pressure transmitter 2, pressure detector 3, temperature detector 4, and 1st arithmetic means 6. When the output DELTAP of the transmitter 2, output P of the pressure detector 4, and output T of the temperature detector 4 are sent to the 1st arithmetic means 6, the means 6 calculates a flow rate QNO against which the temperature and pressure are converted into the reference condition. Then the 2nd arithmetic means 7 finds a moisture correction coefficient KW as the function of the absolute moisture Hf and calculates a moisture-corrected flow rate QNf by multiplying the flow rate QND by the coefficient KW. Therefore, moisture correction of a wet gas can be performing very easily by applying prescribe approximate correc tion of a linear formula irrespectively of the temperature and pressure.
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