As an alternative, you could vent the altimeter differently.
I think at least one altimeter (don't ask me which one as I can't remember) uses
a pressure sensor that has a package designed to be attached to tubing. I also
think that these sensors are designed for use with 1/8" ID tubing that you can
find at your local RC shop for use with fuel systems.
Pick up some tubing and some "T" connectors. Use the tubing and "T" connectors
to connect to three external vents. You could probably make decent vents using
Now your vented volume is almost non-existant. But this might cause a problem.
The usual vented altimeter bay acts like a low pass filter and decreases any
variation in internal pressure caused by wind or other things. The tubing will
not provide this filtering. Depending on the particular software in the
altimeter, this may or may not be a problem.
This could possibly be extended to venting a small internal compartment but it
gets tricky. The recommended vent sizes are based on the depth of the vent hole
being small enough to ignore the flow effects. If you run a long tube to vent an
internal compartment, this assumption is no longer valid.
Brian Elfert wrote:
>>But if you want dual deployment, then you need a baro sensor, which
>>you said you didn't want to use. An accelerometer is also a single
> I guess finding an acceleromoeter only device is not possible.
> I did a little research and found both the Gwiz MC and the AltAcc2 have
> baro sensors and probably require venting. I didn't think the MC or the
> AltAcc2 had baro sensors.
> The problem is my rocket has an 16" long 11.5" diameter altimeter bay and
> requires a ton of holes for venting.
> I suppose I could rebuild the altimeter bay with smaller volume.
> Brian Elfert
David W. Schultz
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