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ILEC Australia |
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For a fuller technical discussion on TE Probe compensation fundamentals, download the definitive Rudolf Brözel article on the subject. Click here.
ILEC TOTAL ENERGY PROBES ILEC manufactures total energy probes for compensation of variometers for gliders. The two hole version is now being used on more than 6,000 gliders around the world. ILEC probes are a proprietary invention using extensive wind tunnel, and actual aircraft testing. These probes are characterised by great insensitivity to side slips and gusts, and feature very low "noise" pressure output. These attributes give excellent total energy measurement properties and result in very quiet variometer readings, especially during circling in thermals where slips and turbulence cannot be avoided. ILEC probes are precision built of high strength, corrosion resistant, anodized aluminum alloy. These light weight probes are less sensitive to oscillation errors than probes manfactured from brass, stainless steel, or other heavier metals. Each probe is built in three parts: The measuring head with holes, the tube, and the plug with an 'o'-ring seal. The plug is available with an 8 mm diameter, and adapter tubes are available for other needs. The probe is simply installed into the receptacle. The 'o'-ring serves as the seal. No taping is necessary. After landing, the tube can be easily pulled out for storage in a safe place. A normal, 500 mm horizontal fin mount, as well as a vertical, 400 mm fuselage mount are available. A special extended length, 900 mm fin mount only probe is also available, which is suggested for Open class, T tail gliders, or those with very fast variometers. MOUNTING ILEC TOTAL ENERGY PROBES Fitting of the tube: On modern sailplanes, a short brass tube which serves as the receptacle for the probe is mounted on the aft fuselage or, more commonly on the vertical stabilizer. These mounts are available from the dealer. Be sure the inner surface of the receptacle is smooth, as any roughness will damage the o-ring seal. Lightly grease the inner surface of the receptacle. (Vaseline works well.) The bore of the receptacle must be smooth and within +.02 -.00 mm tolerance. Position of the tube: It is strongly advised not to position the tube in the vicinity of the wing, or even worse, in front of the canopy. Such positions should only be used on very low performance gliders with a narrow speed range when no other way is possible. If you must mount on the fuselage, try to mount it at least one meter behind the trailing edge of the wing. The position high on the vertical stabilizer is best. The probe head should be in line with the top of the vertical stabilizer, or in the case of T tailed gliders, in line with the horizontal stabilizer. Positions half way up the vertical stabilizer are normally not as good because of the airflow interference with the fuselage, tailplane, fin and the wake of the wing and fuselage. Alignment: You may closely approximate the best position by making the probe parallel with the axis of the aft fuselage cone. A more precise method is to determine the inclination of the glider in flight with the help of a spirit level, at the speed of best glide. Level the glider in this position, and adjust the tube to be level. For fuselage mounts, the base of the stem should be perpendicular with the fuselage. Orientation: On the fin, position the tube so the measuring head is pointed upward. For the fuselage mount, the holes should be pointed aft. Maintenance: The receptacle should be lightly greased from time to time, and be kept clean. Final note: Your probe is a precision instrument. It's functioning may suffer from damage. Protect it by removing it and stowing in a protected place when the glider is not being flown. |
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Copyright © 2008 - Dion Weston Associates, Dave Nadler, ILEC GmbH - All Rights Reserved |
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