Kestrel 4250 (Racing) - Manual (Page 5)

Kestrel ® 4250 Racing Weather ® Tracker
9
SPECIAL FUNCTIONS
Customizable User Screens
The Kestrel Meter has three User Screens that can be customized to display three current
measurements simultaneously. These screens can also be turned off. (See the Main Menu
section for setup instructions.)
Max/Avg for Wind Speed & Wind Chill
The Max/Avg values for the wind speed and wind chill values are measured independently from the stored
and charted data.
This allows the user to start and stop the averaging period in the most appropriate manner for their
application. Averaging on all wind-related values (Wind Speed and Wind Chill) will be started and
stopped together.
While viewing the Min/Max/Avg screen for any of these measurements, hold the unit into the wind, and
press the button when the screen displays “--average” to begin collecting data for all measurements, and
again when the screen displays “--stop” to stop collecting data and hold the values on the display. Press the
button when the screen displays “--clear” to clear the data. This routine will work simultaneously for all
measurements, regardless of which one is displayed while the routine is run. The Max/Avg for these wind
values will not affect any other Min/Max/Avg or stored data.
Manual Data Storage
To manually store data, press the button. One of the following will appear: Data Stored (data has been
captured and will appear on chart), Full (Overwrite is off and data log is full), or Off (Manual Store button has
been disabled). (See the Main Setup Menu section for more information on memory.)
Backlight
The Kestrel Meter has a high-visibility green backlight, which makes the display easily read in low-light
conditions.
Press the button to activate the backlight. The light will remain activated for one minute. Press the
button within one minute to deactivate the light manually.
Relative Humidity
The Kestrel Meter is capable of measuring RH to a high accuracy: +/– 3% RH between 5 and 95%. To ensure
operation within these specifications, please follow these recommendations:
• Avoid taking measurements in direct sunlight, which will heat the air inside the humidity sensor enclosure
and cause inaccurate readings.
• If your circumstances force you to expose the Kestrel Meter to a large temperature swing prior to taking
a relative humidity reading (such as when taking a Kestrel Meter stored inside at 70° F outside to a
temperature of 40° F), you will need to take additional steps to ensure that the Kestrel Meter’s external
temperature sensor is in thermal equilibrium.
- Ideally, provide an wind speed of at least 1 M/S (2.2 MPH), over the temperature sensor—point the
Kestrel Meter into the wind. If there is no wind, simply wave the unit back and forth so air passes
over the sensors. With airflow over the temperature sensors and humidity chambers, readings within
specifications will be provided within two to three minutes, even after a large temperature shift.
- If no airflow can be provided, you must allow sufficient time for the RH value to stabilize. This can take
as long as 20 minutes—the greater the temperature change, the greater the time. You can use the
logging capability of the Kestrel Meter to confirm that the unit has stabilized to a correct reading: Set
the memory options to a relatively short logging interval (20 seconds works well), select the graphical