Rev #37
Version 8.0
April 2021
Page 86 of 121
6
Variometer and Altimeter
All signals from the pneumatic sensors (altitude, speed) are derived from high quality
pressure sensors, which mean that no flask is necessary. The vario signal is derived from
the altitude signal. All signals are temperature and altitude compensated. The colour
display shows the vario information as well as many other parameters.
The display is user configurable. The Variometer can be configured to show:
•
Range
5, 10 and 2.5 m/s or 10, 20 and 5 kts.
•
Time constants
0.1 s to 5 s, in addition there are 4 settings for electronic processing
for the vario signal.
•
Netto
shows the air mass lift and sink.
•
Relative
shows the lift or sink that would be achieved if the glider was circling at
thermaling speed.
There are two ways by which the vario indications can be corrected for total energy.
Electronic TE compensation is based on speed changes with time and pneumatic
compensation with a TE probe. The quality of the TE compensation depends entirely on the
location, size and dimension of the TE tube. The installation must be leak-proof.
If an electronic TE compensation is selected the TE (P
st
) port should be connected
to a good static pressure source. If pneumatic compensation is selected the TE
(P
st
) port should be connected to the TE probe.
6.1
Altimeter
The altimeter of the LXNAV S8x/S10X is temperature compensated from -20ºC up to + 60ºC.
The altimeter is calibrated up to 20000 m.
6.2
Speed Command
Speed command flying based on the MacCready theory is a very useful tool to optimize
cross-country speed. When the instrument changes to speed command mode the audio will
change and become a director informing the pilot whether he is flying too fast or too slow.
To reduce confusion between vario and speed command audio some special features are
incorporated:
•
Continuous audio signal and other kinds of signals can be chosen. For details see
setup.
•
No audio at correct speed (dead band).
TE (Pst)
LXNAV S8(0)
Electronic TE Compensation
Compensation with TE probe
Summary of Contents for S10 Series
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