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Flowmeter Problems

  1. Oct 8, 2014 #1
    Hi there,

    I am currently doing leak testing for a piece of equipment. In order to do so I have a flowmeter at the inlet and outlet (of what is essentially a long cylinder) and have air drawn through by a vacuum pump.

    Now, the problem is that even with no obvious signs of leaks the two flows did not match. As a result I connected the two calibrated flowmeters (one sapphire float and a tantium float) together with the vacuum pump and compared the two flowrates. There really shouldn't really be any discernible difference between the two as the connections are very secure. However, there is a difference of 12 l/min between them.

    Why would there be such a large difference between the two when they are simply connected in series? They have been calibrated by the vendor previously. Are there any inherent problems if you connect flowmeters in series and compare the two flowrates (such as the pressure drop of the upstream flowmeter)?

    Cheers,
    Dave
     
  2. jcsd
  3. Oct 14, 2014 #2
    Thanks for the post! Sorry you aren't generating responses at the moment. Do you have any further information, come to any new conclusions or is it possible to reword the post?
     
  4. Oct 15, 2014 #3
    is it...leaking?
     
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