4250 Racing Weather Tracker with Backlight In a hurry? Be sure to read pages 5-7 to ensure that your Kestrel is setup properly! Instruction Manual for Kestrel 4250 Racing Weather Tracker www.kestrelweather.com Revised 07/29/10 800.784.
3 Kestrel® 4250 Racing Weather® Tracker TEMPERATURE SENSOR Hermetically sealed precision thermistor coiled to isolate from case temperature. IMPELLER Zytec™ V-bearings on a userreplaceable impeller. IMPELLER COVER Swivel cover protects impeller when not in use. MANUAL MEMORY BUTTON Press to manually store current conditions to memory. BACKLIGHT BUTTON Press to activate backlight for 1 minute.
Kestrel® 4250 Racing Weather® Tracker TABLE OF CONTENTS GETTING STARTED. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 NAVIGATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 SPECIAL FUNCTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . .
7 Kestrel® 4250 Racing Weather® Tracker Measurements use and Wind Speed Temperature Humidity Water Grains /Moisture Dew Point Station Pressure Density Altitude Air Density Relative Air Density NAVIGATION The Kestrel 4250 is set up to display 9 Measurements (some are calculations) in 3 Modes. The Measurements are listed here with their corresponding screen icon.
9 Kestrel® 4250 Racing Weather® Tracker 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.
11 Kestrel® 4250 Racing Weather® Tracker display of RH, and you can see when the value is no longer changing significantly. At that point, the RH value is stable and can be relied upon to be within the accuracy specifications. Station Pressure, Barometric Pressure and Altitude Adjustment The Kestrel 4250 Meter measures “station” pressure — the actual air pressure in the measurement location. Station (Absolute) Pressure is what is shown on the “Pressure” screen.
13 Kestrel® 4250 Racing Weather® Tracker BARO screen, since the pressure changes will be due to changes in elevation far more than to changes in the weather. In general, changes in barometric pressure associated with weather changes are small over the course of one day, but they will affect the accuracy of the altimeter over time. This is why aircraft reset their altimeters at every airfield by entering the field’s “altimeter setting” or reference pressure.
15 Kestrel® 4250 Racing Weather® Tracker Overwrite (On/Off ) Man Store (On/Off ) This setting only applies when the data log is full. When On, oldest data point is discarded to allow memory for the new data point. When Off, new data points are not saved. Press or to toggle between On and Off. When On, data is stored when the button is pressed. When off, the button is disabled. Press or to toggle between On and Off.
Kestrel® 4250 Racing Weather® Tracker User Screens The three User Screens can be reconfigured to display the most appropriate information for your application. For example, if you need to monitor the wind speed, humidity and barometric pressure, a User Screen can display these current measurement values on the same screen for quick reference. Only current measurements can be selected for the User Screens — Min/Max/Avg and Charts are not available. Highlight the desired User Screen by pressing the or button.
19 Kestrel® 4250 Racing Weather® Tracker APPLICATION EXAMPLES This section provides examples of applications where a Kestrel Racing Meter might be used, and the appropriate memory settings. Weather Monitoring for Race Weekend Auto Store On Store Rate 1/2 hr Overwrite On Man Store On These settings will allow you to track conditions for 1 month. When the memory is full, each new measurement will be stored in place of the oldest data point.
21 Kestrel® 4250 Racing Weather® Tracker GLOSSARY The below definitions have been greatly simplified in order to keep this section brief. We strongly recommend that anyone who wishes to make use of these measurements refer to one of the many excellent weather references available for a more in-depth definition. On the internet, visit www.usatoday. com or www.noaa.gov. Or, locate the USA Today publication, The Weather Book.
23 Kestrel® 4250 Racing Weather® Tracker Temperature The ambient air temperature. Wet Bulb Temperature The lowest temperature to which a thermometer can be cooled by evaporating water into the air at constant pressure. This measurement is a holdover from the use of an instrument called a sling psychrometer. To measure wet bulb temperature with a sling psychrometer, a thermometer with a wet cloth covering over the bulb is spun rapidly through the air.
25 Kestrel® 4250 Racing Weather® Tracker Think the weather conditions at the track are the same as the information you are getting from back at the trailer? Think again. Even slight changes in air density, water grains, and density altitude can dramatically affect a machine’s performance.
Kestrel® 4250 Racing Weather® Tracker I don’t have E.T. prediction software, any help you can offer how I can dial in with the Kestrel alone? We went to the experts to get an answer for this one. Here’s how they do it at Martino Motorsports: The density altitude reading is the most important to us. For every 150 ft. increase in DA, our car will lose .01 in elapsed time, and for every 150 ft. decrease our car will pick up .01 in elapsed time. But we can get the same DA and have two completely different runs.
Kestrel® 4250 Racing Weather® Tracker 29 CUSTOMER SERVICE remedy with respect to any breach of the NK Limited Warranty set forth herein. All product liability and warranty options are governed exclusively by the laws of the Commonwealth of Pennsylvania. NK does not believe in “disposable electronics.” We know that Kestrel Meters don’t typically lead pampered lives, and we design them for years of performance in tough conditions.
31 Kestrel® 4250 Racing Weather® Tracker with N.I.S.T. requirements and based on a regular schedule. Only approved laboratories and N.I.S.T themselves are used for these calibration services. Incoming and outgoing data is supplied with the certificate of calibration. We also offer full factory service on every product we manufacture for as long as we make the product (and as long after as component availability permits).
Kestrel® 4250 Racing Weather® Tracker Kestrel® Pocket Weather® Meters are designed and manufactured in the USA by: NIELSEN-KELLERMAN 21 Creek Circle, Boothwyn, PA 19061 Phone: (610) 447-1555 Fax: (610) 447-1577 Web: www.kestrelweather.com Email: kestrel@nkhome.com Please register your Kestrel Meter at www.KestrelWeather.
