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Starting vacuum tightness check

Written by Ryan Hunt on .

Thur, Sept 20th

The first cell is in the lab getting a vacuum tightness check at the moment.  It is pumping down slowly because of the long, small tube connecting it.  This is the best way to verify the seal tightness initially.
Next steps:  
-attach voltage sense wires near the cell
-Hook up the power supply and instrumentation
-Try heating test in vacuum
-try pressure test cold, and then hot
-Then power vs. final temp in Helium at multiple pressures
-Then power vs. final temp in Hydrogen at multiple pressures
 
Meanwhile we will be assembling the second unit, also.  Once we are sure the design holds pressure and temperature, we can send it to Nicolas and Mathieu to become familiar with and test.  We will be watching the air flows and temperatures and how the shield is making it behave before we decide if we want to enhance the convection.
 
Someday soon I also want to assemble an extra one and pressure it up till it explodes and verify that the safety shell is up to it.  Plus it will make some great video.
 
Below we see the cell sitting in our lab hood where we will do most of our testing.  Our hood vents outdoors and is in a well ventilated lab in a small annex building we made with walls and windows that could blow off easily to limit the over-pressure in case of an explosion.  Then we put the hydrogen storage tank in the ventilation hood, put a flow limiting orifice in the regulator, and added a hydrogen gas detection alarm that makes an audible alarm and triggers max ventilation.  
 
 
Here we see Malachi working connecting the thermocouples to the instrumentation package.
 
That is a better way to handle the wires.  The terminal strip has the power connections for the two wires and the voltage sense connections.  Sensing the voltage on the test wires from as close as possible to the cell makes the power readings a little more accurate.
 
 
 

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