Used pitot tube questions
 

I bought a 12v used/salvaged pitot tube and have a couple questions. The two wires are not labeled, does it matter which one is ground and which is wired to the power? Can anyone tell from the picture which is ground - the connector style is different for each wire -so maybe that has some meaning to someone. Thanks for your help!

http://img207.imageshack.us/img207/1830/p1010018id0.jpg

Todd Neidinger
RV-9A wings

Todd, the heating element is purely resistive. Polarity isn't an issue with it but, if the manufacturer grounded one side of the element, that will determine polalrity.

Take an ohmmeter and go from each wire to the shell of the tube. If one reads zero (or real close to it) that one is negative.

My guess is neither one will so either one could be negative, your call.

:) CJ

Mine is totally insulated from the shell also, and doesn't matter polarity wise.

BTW-- don't over tighten the screw on the phonolic connector (if you have one). I cracked mine! What use to be less than $10.00 is now a shade under $70. Inflation or liability? :D Of course the heated pitot is now over ten times what I originally paid!

Thanks - thats is what I thought, but nice to make sure. Now for the really hard question - where can I find the #6-40 screws that are used to hold this to the pitot mast?

Todd

Here's some pretty spiffy ones:

http://www.amazon.com/Alloy-Steel-Socket-Screw-Length/dp/B000FN82CA/sr=1-2/qid=1164596761/ref=sr_1_2/103-9425359-2531027?ie=UTF8&s=industrial

I googled up "stainless 6-40 screws" and a whole bunch came up!

:) CJ