LXI LX7007 - Manual (Page 44)

LX 7007 pro IGC V1.0 Apr.2005
Page 44
2.3.1 Smart Vario description
The LX system incorporates two configurable electronic filters in the circuitry. The first filter adjusts the time constant
and is adjustable between 0.5 and 5 seconds. The 0.5 setting is the fastest while the 5 setting provides maximum
damping.
The second filter, called the Smart Vario, is a dynamic filter and controls the rate at which the vario indication moves.
When set to OFF, there is no restriction on the rate of movement of the vario indication other than the setting of the time
constant filter. When set to 1, the vario indication will not move faster than 1 m/s (2 kts) per second, while when set to
4, the vario indication will not move faster than 4 m/s (8kts) per second. It should be noted that when set to 4, the vario
indication will move four times faster than when set to 1.
Summary:
• The Smart Vario should not be used in isolation but in conjunction with the setting of the time constant filter.
When the Smart Vario is activated, the time constant filter may need further adjustment to provide optimum
indications.
2.3.2 Altimeter
The altimeter of LX 7007 PRO IGC is temperature compensated from -20ºC up to + 60ºC. The altimeter is calibrated
from 0 to 6000m (20,000ft), but indication goes up to 8000m (26,000ft). The displayed altitude can be based on the
airfield elevation (QFE) or the local QNH which is set in the initialization screen after switching on.
2.3.2.1 IGC barogram recalibration procedure
LX 7007 PRO IGC has an additional pressure sensor for altitude recording. To comply with IGC procedures, this
sensor has no external pneumatic connection. To carry out the baro calibration procedure it is necessary to remove the
instrument from the glider and place it in a vacuum chamber. The procedure is as follows:
• Switch the instrument ON, and wait some minutes (straight line on the barogram beginning)
• Set logtime to 1 second
• Place it in the chamber and carry out a short climb to about 1000m
• Bring the chamber pressure to exactly 1013.2 hPa
• Decrease the pressure by 1000m and hold for about 30 seconds
• Continue the procedure to 6000m
• Increase the pressure in 1000m steps back to 1013.2 hPa
• After reaching ground wait about 3 minutes and switch the instrument off
• Leave the instrument minimum 5 minutes off
• Read and print the barogram using the Lxe PC program
The barogram will be the last flight in the logbook.
2.3.3 Speed command
Speed command flying based on the McReady theory is a very useful tool to optimize cross country speed. There are
many visual indicators (see LCD Vario). 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. In order to reduce confusion
between vario and speed command audio, some special features were developed:
FILTER
0.5 to 5
SmartVario
FILTER
1 to 4 or OFF
RAW VARIO FILTERED
VARIO VARIO
INDICATION