DIY Altitude Chamber
 

Winter can be a good time to do stuff.
This winter three of us decided to learn about the electronics, characteristics, limitations, and capabilities of a couple different altitude recorders.
On the test bed: Jolly Logic's AltimeterThree, PerfectFlite's StratoLogger SL100, and EggTimers Quark.

The JL3 and SL100 are fully assembled and just about ready to fly out of the box, the EggTimer Quark requires assembly (at the component level - our build video is in work).

We wanted to comprehend the drogue deployment, main deployment, and altitude recording of the SL100 and Quark. The JL3 provided us with a device to compare the results along with readily accessible metrics (graphs and spreadsheets).

We discussed strapping a few Ms onto a lawn chair and going up with the computers to witness the apogee events and main chute events; we scrapped that idea when the wives began supporting the effort.
A moment of clarity came to Scott while in the shower... why not use the Food Saver with the marinating containers, put the devices inside and 'launch' them in our defacto altitude chamber!?

The rest is history... for your viewing pleasure; a test of the Quark & JL3, followed by a test of the SL100 & JL3, and finally, the Quark, SL100, and JL3 along for the same ride.

Quark and JL3
https://youtu.be/mepctW1FLaI

SL100 and JL3
https://youtu.be/aZWsy8mDUYM

Quark, SL100, JL3
https://youtu.be/e_KTH2DmwM0

Brilliant!

Proof of Concept / Validation
 

Note to anyone watching... the little DIY altitude chamber experiment paid for the time and energy.

We bought three Egg Timer Quarks, one for two adults and one teenager, moderate soldering skills for the adults, and a new experience for the youngin.

We built one Quark - tested, all was right (startup, tones, continuity on LEDs [simulated ematch], and firing of drogue/main charges [again LEDs simulated the output])
Built the next Quark - tested, all was right
The last Quark was assembled, startup was good, good tones, continuity on LEDs, and ready for launch signal. When we did the altitude chamber test, the apogee event did not occur (the LED did not get super bright like the other two tests), however, the main chute event (approx. 500' AGL) did occur.
We're troubleshooting the possibilities (EggTimer customer support has provided rapid responses) and hope for full resolution.

The key to this, I asked the youngin - "Imagine if that was in your rocket, and the drogue chute did not fire"; he immediately realized the value of the simplistic test.

So, proof of concept - at least on a barometric level. We'll have to trip the accelerometers through an actual launch!