Gas state conversion

In the conversion of gas states, the formula commonly used is derived from the ideal gas law. The ideal gas law is PV = nRT, where P is pressure, V is volume, n is the amount of substance, R is the gas constant, and T is temperature. When the gas state changes, different formulas can be derived from this equation to express the relationship between the gas states. For example, when pressure and the amount of substance remain constant, the relationship between gas volume and temperature can be expressed by the following formula: V1/T1 = V2/T2. There is no square root in this formula, as it can be shown through derivation that there is a linear relationship between temperature and volume. However, under certain special circumstances, the transition of gas state may not conform to the ideal gas law. For example, when determining the oxygen mass transfer performance of clear water using micro-porous aerators, more complex physical and chemical processes must be taken into account, requiring more accurate models to describe the changes in gas state. These models may contain more variables and parameters, resulting in nonlinear forms such as square roots in the formulas. In the **industry standard CJ/T 475-2015 you mentioned, the use of the square root may be due to the special properties of gas state transformation discussed in that standard. In specific cases, the square root may be used to better describe the complex relationships in the process of gas state transformation. Therefore, in this case, the formula in radical form is correct in this standard. In summary, different problems related to gas state transitions may require the use of various formulas and models for description; it is very important to choose the appropriate formula depending on the specific circumstances. .

Thank you very much:handshake

One more question: both formulas involve the conversion of flow rates, but why does the upper formula have a square root while the lower one doesn’t?

The standard is written correctly. Since a rotameter is specified here, if it were a mass flow meter, only the conversion method in Equation 15 would need to be considered during the conversion process. The use of a float to balance the rotor in rotameters means that density must be taken into account in the conversions, and thus the final formula is as specified in the standards. It is recommended to refer to the principle of rotameters or float flowmeters.

I tried to send the principle formula for a rotameter, but it failed twice; please search for it on your own.