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Is this a right way to detect leakage?

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Old   July 19, 2014, 08:26
Question Is this a right way to detect leakage?
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Mehdi
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Hi,
I am going to find a way to detect leakage of an H2 filled tube automatically. Pressure and temperature of gas are monitored continuously. The exact volume is not given. one pipe is open to the tube to maintain the tube pressure and its flow rate is being monitored. I have written this instruction to detect probably leakage:

Suppose we have a given amount of ideal gas within a sealed tube. This equation is always true: PV=nRT
The "nR" is constant. With derivation method: dP/P1 + dV/V1 = dT/T1
Then after a specific time: dP/P1 - dT/T1 = P2/P1 - T2/T1= -dV/V1
So if we insert a specific volume of gas, it reduces the volume which our first amount of gas occupies. Volume difference is: Vn=-Q.t
Q is flow of input gas and t is time. But the volume of new gas will vary after settling in the tube. If new gas obeys ideal gas law and its pressure difference supposed almost zero, then temperature and volume of new gas will have this equation: Vn=Vn0(T2/Tn0)
Which Tn0 is new gas initial temperature. So difference in volume of old part gas will be: dV=-Qt(T2/Tn0)
The equation for our first gas, becomes: (P2/P1)-(T2/T1)=Qt(T2/Tn0)/V
When we are sure no leakage is there and P,T and Q can be measured over time, then V can be estimated according to the equation above. After that during process continue, if someone is going to check the leakage, calculating E in this equation will be enough for him/her: (P2/P1)-(T2/T1)=Qt(T2/Tn0)/V-E

Please tell me what is your idea about it whether is practical or not? Thanks
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