How to perform temperature and pressure compensation for gas flow rate
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I know that generally, temperature and pressure compensation is required on a DCS when measuring gas flow rate. Could someone explain how this compensation is calculated, what formulas are used, and what data is needed? I would be extremely grateful if anyone could provide a detailed explanation. .
Learn in the front row*. Nowadays, many flowmeters come equipped with built-in temperature and pressure compensation.
For gas flow measurement, whether in an integrator or a DCS, the flow calculation procedures are modular; it is only necessary to collect the temperature and pressure signals into the DCS as required.
This post was last edited by cqdfwy on 2019-7-9 at 10:23. Gas flow rate, temperature, and pressure compensation are all calculated based on the principles of the gas state equation.
Typically, the temperature and pressure at the installation site differ from those specified during design; therefore, most instruments are capable of measuring these values at the site, and then automatically compensate for them using mathematical formulas. For example, in the measurement of air flow rate, flow meters such as VeriMa and Anemone measure the volumetric flow rate under the actual temperature and pressure conditions. However, when the volume of air remains constant, its mass is greatly affected by temperature and pressure; therefore, the instrument must first measure the temperature and pressure at the site before performing automatic compensation. In general, the purpose of temperature and pressure compensation is to convert values measured under conditions other than standard conditions into corresponding values measured under standard conditions, ensuring that the results from different measurements are on the same scale, which facilitates comparison and statistical analysis.
Temperature and pressure compensation is generally required because the flow meter selected measures the volumetric flow rate under operating conditions. Flow rate + pressure + temperature, compensated using the ideal gas law.