- Wind Speed - Average over the previous three seconds. The measurement will be accurate for air flow through the front or rear of the unit.
- Maximum Wind Gust - Maximum 3-second wind speed since the unit was turned on.
- Average Wind Speed - average wind speed since the unit was turned on.
- Temperature - Instantaneous temperature of the thermistor, which is located at the end of the long coiled leads in the open cavity below the impeller. The exposed thermistor will respond quickly to changes in temperature when air flows past it. For fastest response, either hold the unit into the wind or wave the unit side to side for 15 seconds. Readings should be taken in the shade.
- Wind Chill - Combination of wind speed and temperature, as defined by the US National Weather Service. Wind chill is the effective temperature on a human or animal at low temperatures due to wind speed. Wind chill readings will be the same as the temperature readings above 45繙F or below 3 mph.
MAINTENANCE & TROUBLESHOOTING
Every Kestrel Meter is fully waterproof and floats, and has passed mil-spec drop testing.
Storing Your Kestrel
Avoid storing your Kestrel where it will be exposed to temperatures below -30簞C [-22簞F] or above 60簞 C [176簞 F] for extended periods of time. Doing so may cause permanent damage. (Note that the inside of a car parked in the hot sun can reach very high temperatures.)
Use of the Lanyard and Cover
The cover can be captured on the lanyard to avoid loss. First, remove the cord poplock. Then feed the lanyard end through the large opening in the over and out the slot. Replace the poplock on the lanyard.
Replacing the Battery
When your display becomes dim or disappears, replace the battery. Use a large coin to open the battery compartment. Use only new CR2032 coin cell batteries (available where watch batteries are sold). Wipe the battery clean of any fingerprints and insert the positive (+) pole up, angling the battery downward and pressing it firmly into place. When replacing the battery door, be sure to keep the black rubber o-ring seated in the groove on the case back.
Why does the Impeller Appear Imbalanced?
It is NORMAL for the impeller to oscillate as it comes to a stop. It is NOT imbalanced. Rather, it contains a very small magnet that responds to the earth?？ magnetic fields. This does not affect the accuracy of the wind speed readings because the magnetic field applies both a braking and an accelerating force which cancel each other. The impeller has been calibrated to provide wind speed readings accurate to within at least 簣 3%.
High Speed Use
After several hours of sustained operation over 25 M/S (~49 KT, 90 KM/H, 56 MPH or 4,923 FPM), the Kestrel will lose some accuracy due to wear of the sapphire bearings in the impeller.
Replacing the Impeller
You may recalibrate the wind speed readings by replacing the impeller. Press FIRMLY on the sides of the black impeller housing with your thumbs to remove the entire assembly. When inserting the new impeller, be sure the arrow is facing the display side of the unit, and is aligned with the top of the meter. Press on the sides of the housing rather than the center.
The Beaufort Scale is a system for estimating wind force without the use of instruments based on the visible effects of the wind on the physical environment. The behavior of smoke, waves, trees, etc., is rated on a 13 point scale. The scale was devised in 1805 by the British naval Commander Sir Francis Beaufort (1774-1857) and is still commonly used by mariners.