strange ASI readings on LXNAV s80 vs Winter ASI

On Wednesday, February 14, 2018 at 10:27:22 PM UTC-8, Doug C wrote:
On Wednesday, February 14, 2018 at 8:38:38 PM UTC-5, Matt Herron Jr. wrote:
looking for some instrument debugging help.

I have a steam gauge ASI (winter) and an LxNav S80 sharing the same Pitot and static lines. In the air, the two gauges read ASI differently. The S80 reads about 10 knots higher than the Winter at 70 knots, and 5 knots higher at 40 knots. The error seems to scale with higher airspeeds

Back on the ground we used a syringe to pressurize the pitot line. Both instruments read within 2 knots of each other for the full speed range. they also held steady at the desired airspeed with the syringe, indicating no leaks in the Pitot system.


Back in the air, I tried opening and closing the vent, scooping air into the cockpit to pressurize it, etc. Neither instrument changed its reading, but the offset in speeds remained.

Ideas? Leak in Static?

Matt

Hi Matt:
I experienced the same problem when I received my S100 early last year. Uros sent me the following solution which autozeros the pressure sensors. His suggestions completely solved the problem for me.
Best regards
Doug
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Hello,
please check under setup-vario, that you have airspeed offset set to 0.

Please enter password 01043, to make autozero on pressure sensors.

Best regards, Uros
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Thanks Doug, I will give that a try. As far as units go, both instruments indicate knots.

Matt