Perhaps a hydrogen rated pressure switch like this one? Not sure how much it would cost though.
https://www.te.com/usa-en/product-CAT-PTT0036.html
Servoflo also makes good solid state sensors:
1 Like
John got us connected with the board to see which days we’re good for a fill-n-launch in the parking lot. Possible days would be this Wednesday or next week Tuesday, Wednesday, and/or Thursday.
The pressure sensor doesn’t have to be hydrogen necessarily. It’s more to protect the PEM from damage. So something like if: pressure > 80psi in the tank then: disconnect solar circuit
Right now I’ve got an MQ-8 hydrogen sensor that costs $3 that was really helpful for finding small leaks in the fittings. But it’s cool to know there are other hydrogen-specific pressure sensors out there. Could be useful for anyone wanting to measure “green-hydrogen” volume for a company that deals in Carbon offsets.
1 Like
If done in the parking lot on a weekday, do it very early in morning - l say before 07:30 or after 17:30. Reason: lots of traffic, especially trucks. Otherwise I’d recommend a Saturday.
If you can do it in the area near the building but not extending past the the end of the ramp/marked fire lane, the probably okay anytime But this puts it closer to the building than you’d like.
Wind is a biggie, I would suggest it has to be between ENE to ESE (i.e. away from our building) otherwise it could float into the MAJOR tall power lines out front running N-S.
Definitely agree. The board agrees with you about the power lines. We got approval from the board to set it up the hydrogen generator and panels a few days this week and next week, but they’ve asked that we complete the launch elsewhere due to the power lines and FAA restriction.
According to DJI fly map here, the Makerspace itself isn’t in any Restricted or Altitude zones. But to play it safe, let’s do the physical launch at Cox Field.
13550 Dennis Ln, Farmers Branch, TX 75234
I like to do my launches at the same exact time as the official NWS balloon launches in Fort-Worth, so that I can compare the data. That would put us at first launch tomorrow (Wednesday) at 6pm after generating the hydrogen over the course of the day.
3 Likes
Is the NWS balloon data publically available? Where?
Sounds like you are having fun and helping projects in Africa.
1 Like
Yes, it’s a great project and get to work with a lot of smart individuals! The NWS publishes the data roughly 2-4 days after each launch. The dataset is called IGRA2 and can be found here:
https://www.ncei.noaa.gov/access/metadata/landing-page/bin/iso?id=gov.noaa.ncdc:C00975
There’s also a Python library called metpy that can parse the data if you care to program.
2 Likes
Looks like it will be a bit too cloudy and windy to get enough sun on the panels today.
Let’s shoot for Tuesday of next week. There’s a good chance of rain Monday and the rainwater system should be functional well before then.
1 Like
First rain. With help from Taylor and Purnie, it’s sitting outside Woodshop bay doors the next couple days.
4 Likes
Thanks to everyone who helped with the launch after the science meeting today.
About 70 minutes into flight it reached minimum pressure of 297 millibars or about 30,200 feet . Last packet received near Wylie, Texas shortly after.
6 Likes
Sounds like you need a bigger battery!
1 Like
Ha, no 400mah is perfect! It held up for 4 hours on a launch a few days ago, and only needed 90 minutes.