Nasa Wind

[Allan]

We are preparing for our return from the USA and have a problem with the Nasa Wind instrument. It had stopped showing direction due to corrosion on the head unit. We removed the head unit and cleaned up the corrosion, now it is not working. When the unit is plugged in it works for a short time (2-3 sec) then stops and reads zero. Is this a known problem? It doesn't seem like the connections are at fault.
Allan

 

[Twister_Ken]

See threads previous. NASA Wind masthead units are carp (anagram). Sorry about that.

 

[[70521]]

Give the really nice people at NASA a ring, they are really, really helpful.

 

[Allan]

I have just seen that there are two types. One has a red wind vane the other, like ours, a white vane. The red one says NEMA, which I believe only has two wires not the four plus screen we have.
Life is too complicated! We only have 3900 miles to go, may have to do without!
Allan

 

[whiteoaks7]

You've actually got five working cores in the mast wire because the screen carries current (I think the return but that may be too logical for NASA). One core carries +5V for the masthead unit, two have a differential signal which gives direction and one provides a pulse the period of which is proportional to the windspeed. At the back of the instrument good ol' NASA have that ropey old DIN plug which connects the cores from the mast to the instrument. There they do excellent things like joining black wires to red ones and the like. ... and yes, mine has been in bits so many times I know it inside out and ... no I still can't get it work reliably.

One point though is that the circular magnet that gives direction certainly does corrode to nothing if it gets wet.

Good luck,

Dave Berry