Calculation of the pumping volume for a vacuum pump
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Hello, teachers. While looking for the formula for the pumping speed of a vacuum pump, I came across two formulas: 1. S=2.303V/tLog(P1/P2) 2. S=(V/T)*(P1/P2). Question 1: Which one is correct? Question 2: If formula 1 is correct, what does the value 2.303 represent in this formula? (No information regarding this value was found in any references.) Question 3: Can the amount of gas pumped be determined using the results obtained from these formulas?
2.303 is an approximate value of the natural logarithm with base 10; that is, ln10≈2.303
You can try out the spreadsheet I created at https://bbs.hcbbs.com/thread-1887776-1-1.html
We generally determine the specific pumping speed based on experiments, using a mass flow meter and measuring the vacuum level; as the mass flow increases, a curve that tends to level off is obtained in the end