Vogtlin SmartTrak 100 Series, Руководство пользователя

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Vögtlin Instruments Instruction Manual SmartTrak
®
100 Series
93
Pressure Drop & Hyper-Cooling Cautions
For specific minimum required pressure drops for given flow rate, gas and known inlet pressure, consult the
factory. Flow of high pressure gases through a constriction causes cooling, because the gas robs latent
energy as it transitions energy from potential to kinetic. This is a function of compressibility, the heat
transfer coefficient, thermal expansion coefficient, and other gas properties. Simply put, as gas expands
rapidly, it cools down. This effect is known as hyper-cooling or more technically known as the
Joule-
Thomson effect .
This effect is magnified by the flow rate vs. pressure, with the largest magnitude of hyper-cooling occurring
in cases of high flow rates with large pressure drops across the flow meter or controller control valve. For
best accuracy and performance, it is recommended that a form of thermal packing, gas temperature
conditioning, convective heating, or line heating be employed to mitigate this effect.
Vögtlin is not
responsible for variation in calibration due to gas or system conditions.