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NorthernWidget-Skunkworks / Project-Walrus

TP-DownHole on a one-sided board for easier production and encapsulation
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Housing size / MEMS membrane access #8

Closed awickert closed 3 years ago

awickert commented 4 years ago

From email from @superchap123

"Do we have a maximum size that we want to consider to limit contaminants reaching the sensor membrane? Are we concerned about this?"

awickert commented 4 years ago

I have no specific housing size in mind. The most likely damage to the sensor would be from sediment; having some kind of screen would be good. Will take some balancing: finer screens out more particles; coarser ensures that pressure can be transmitted quickly enough that the sensor readings are accurate.

To answer more directly, I don't think that size should matter.

One related thought: we should see if we can isolate the membrane as much as possible from water with appreciable velocity. This way, the unit could be used outside of a stilling well. (I know I've mentioned this over email, but thought good to put here too; can open a separate Issue.)

awickert commented 3 years ago

@superchap123 created a design that may not perfectly isolate sediment (we will have to test) but does a good job of removing the transducer from the effects of the surrounding velocity, effectively giving it its own self-contained stilling well. This has not yet been tested in moving water. 15a6ea1ceea464b84c4a1b21669ceb5cb8cb5855