Difference: WorkDiary2017 (1 vs. 2)

Revision 217 Jan 2017 - MarkWard

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META TOPICPARENT name="MarkWard"
-- MarkWard - 16 Jan 2017
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  High pressure behavour looks consistant, theoretical pumpdown of an 80 l chamber from the above pumping curve predicts roughly the same pumpdown curve.
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Hornet Gauge and Omega gauge when converted to same units look well matched
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Hornet Gauge and Omega gauge when converted to same units look well matched.

Performed two rate of rise measurements, both appear to be linear with a very slow curve developing. This usually indicates a leak, though cannot rule out outgassing, the elastomer seal on the vessel always smells which means it is outgassing significantly.

Points to check/reseal to be sure are - NPT fitting on the manometer type gauge. Leak rate (if it is a leak) comes out at roughly 10^-3 mbarl/s which is fairly high... even for outgassing.

 
META FILEATTACHMENT attachment="GaugeLinearity.png" attr="" comment="FirstPumpdown Test with notes" date="1484574163" name="GaugeLinearity.png" path="GaugeLinearity.png" size="55680" user="udap005" version="1"
META FILEATTACHMENT attachment="ScrollVac.png" attr="" comment="" date="1484576111" name="ScrollVac.png" path="ScrollVac.png" size="56481" user="udap005" version="1"
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META FILEATTACHMENT attachment="LeaksvsOutgassing.png" attr="" comment="" date="1484670416" name="LeaksvsOutgassing.png" path="LeaksvsOutgassing.png" size="29652" user="udap005" version="1"

Revision 116 Jan 2017 - MarkWard

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META TOPICPARENT name="MarkWard"
-- MarkWard - 16 Jan 2017

Performed a pumpdown and vacuum hold test to ensure equipment is operating as expected.

Attempt to determine when the Pressure gauge (Omega manometer type) 209x becomes none linear due to reaching its zero point.

This appears to occur at approximately 1.6psia or 80torr

GaugeLinearity.png

Hornet gauge remains good till flattening off due to significant pumping speed reduction below approx 3torr (4mbar) for the scrollvac5

ScrollVac.png

High pressure behavour looks consistant, theoretical pumpdown of an 80 l chamber from the above pumping curve predicts roughly the same pumpdown curve.

Hornet Gauge and Omega gauge when converted to same units look well matched

META FILEATTACHMENT attachment="GaugeLinearity.png" attr="" comment="FirstPumpdown Test with notes" date="1484574163" name="GaugeLinearity.png" path="GaugeLinearity.png" size="55680" user="udap005" version="1"
META FILEATTACHMENT attachment="ScrollVac.png" attr="" comment="" date="1484576111" name="ScrollVac.png" path="ScrollVac.png" size="56481" user="udap005" version="1"
 
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