Dual (redundant) altimeter preflight checks

[rewilfert]

For those that fly dual (redundant) altimeters. How do you confirm that both altimeters are powered up and functioning correctly?

When first powered up, altimeters typically emit a series of beeps to give their functional status. If you are running dual (redundant) altimeters, what method do you use to determine if each altimeter is powering up and functioning correctly? Obviously, you can listen to the beeps. But when both are powered up and beeping inside an electronics bay, you can't discern which altimeter is beeping.

I'm looking for a good way to verify correct functionality of each unit when the rocket is powered up on the pad before launch.

 

[5x7]

Perfect flight stratologgers and ravens report readiness differently and beep at a different pitch. The raven start up is fast and you can confirm quickly it’s ready. PF stratologgers beep out a lot of info before being ready, so those two in one bay are a good combo.

 

[cerving]

Two indentical altimers will rarely beep at exactly the same time, and some of them will let you vary the pitch. If you have to different altimeters, the beeps will be most likely be quite different, so it should be easy to tell. The Eggtimer Quantum and Proton are WiFi-enabled, you get the arming status on your phone, so you really don't have to listen for anything. We originally weren't going to put a buzzer on them, but our focus group told us over a few beers that it was a bad idea because people are used to hearing something...

 

[jd2cylman]

MissileWorks RRC2+'s have a adjustable dip switch to select high or low tone.

 

[MikeyDSlagle]

Yep, most have different tones. RRC3 also has variable tone. The Quark just kinda warbles when ready. Some have LEDs that show status as well.
Mix and match devices.

 

[Cory]

Differing tones is enough usually to differentiate regardless as has been said. I always power on the first altimeter and wait for continuity beeps before powering on the second or next altimeter and this helps ensure I am listening correctly.

 

[blackjack2564]

I power up 1 first, when I am sure all is proper I shut it off and power up2.
After going through the warm up if all is well, I just power up 1 again and done!

 

[Nytrunner]

Stratologger also has beep frequency adjustment. I haven't used 2 strats in 1 rocket, I usually pair 1 with an RRC3

 

[rewilfert]

I power up 1 first, when I am sure all is proper I shut it off and power up2.
After going through the warm up if all is well, I just power up 1 again and done!

In my case, I'm going to be using two of the same altimeters (Raven 4) and you can't alter their tones individually or see their status LEDs inside the rocket.

This was the best procedure I could come up with on my own. By checking each altimeter individually, there is no question where the beeps are coming from and you should be able to clearly obtain the status of the powered up altimeter. In theory, you could have something within the altimeter fail on power up, but I think the odds are more likely that something didn't get connected correctly or the programming is incorrect. Once you confirm proper operation of each unit individually, you should be able to just listen for additional beeps from the last unit to be powered up (just to make sure it came on, without interpreting them) and be good to go.