Sunlight and altimeters

Did I read somewhere that altimeters (and/or other avionics) should not be exposed to sunlight during a flight? Something about them possibly being effected by strong sunlight (not necessarily the heat)?

I can't think of why this should matter, but I seem to remember it being discussed as a no-no.

Anyone have any info regarding this?

thanks, s6

My RRC2 instructions have in them directions to avoid intense light including direct sunlight, or any other extreme environmental conditions, hot, cold, wind while armed. I don't see much of a problem with it inside an avbay, unless you have a clear tube.

The barometric sensors are light sensitive. In an av-bay it is not a problem in most cases. When its outside, live and hooked up to charges is when you need to be cautious.

Dang it. I had an idea for avionics setup (altimeter, GPS, etc) built into a 54mm nosecone. Those new glass/polycarb nosecones are pretty sweet, and the INSIDEs of the them are great for such things as there's lots of room and they are smooth, consistent, etc.. I was thinking about using one of the clear ones for a cool effect - all those electronics and wires and such inside a clear cone!

I gather this is not a very good idea. Too bad, I think it would be fun.

s6

Not a problem. If your altimeter mounts its baro sensor on the bottom of the board you are fine. If its on the top of the board facing outward just fab a shade for it, a loop of masking tape will do.

It's not general sunlight that causes a problem its just the case of the sensor hole pointing DIRECTLY at the sun, the little hole acts like a pinhole camera on the piezo sensing element and it goes crazy.

However the "Greenhouse" effect may it to get a little toasty inside.

Question: What causes the transient spikes in the altitude trace of a Featherweight Parrot/Raven altimeter? I don't have the manual with me but I thought it had something to do with spin and the static port? Didn't effect the performance and not seen in a Perfect Flite MAWD. Kurt