Leak tests

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Leak tests
G. Apeldoorn, P. Vankov 29.01.2004, NIKHEF
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Leak tests

29.01.2004
Tests are based on using AFS 1400
Bidirectional Mass Flow Meter
(http//www.sensirion.com)

• Characteristics of AFS 1400
• - dynamic range 0.03 400 sccm
• Fast response time 150 ms
• Calibrated Temperature compensated (for air
  Nitrogen)
• Digital output signal (RS-232)

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Leak tests

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opened
Flow meter
F1 1.023e-6 l/s F2 -1.621e-7 l/s F3 -1.391e-7
l/s F4 1.057e-7 l/s
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Leak tests

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shorted
Flow meter
F1 1.014e-6 l/s F2 -1.441e-7 l/s F3 -1.244e-7
l/s F4 8.529e-8 l/s
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Leak tests

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Temperatures
Flow meter
Flow meter
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Leak tests

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Connection in series
Brooks mass flow controller
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Leak tests

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Leak test of Module 5012 (5m prototype)
Leakage criterion Leakage flow must be of the
order (or less) of 1e-6 l/s.

• Steps
• 0. Tap 2 is always closed.
• Tap 1 is opened, gas is pumping the module in.
• Tap 1 is closed, module is under 8 mbar
  overpressure, F1 is measuring.

(N)
Module
1
2
closed
F1
Bubbler (8 mbar)
Flow meter
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Leak tests

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Leak tests

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Gas volumes (straw/outer) separation
straw
straw
outer
outer
Module
Gas
straw
straw
F1
F2
outer
outer
Flow meter
Flow meter
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Leak tests

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Gas volumes (straw/outer) separation
straw
straw
outer
outer
Module
Gas
straw
straw
F1
F2
outer
outer
Flow meter
Flow meter
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Leak tests

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How to proceed ?

• Better tubes taps
• Atmospheric pressure temperature monitoring
• Flow controller
• Nitrogen/Argon