Kestrel 4000 User manual

1
Revised 09/07
Instruction Manual For Kestrel 4000 &
Kestrel 4000 NV Models
4000
Pocket Weather®Tracker
with Backlight
www.kestrelweather.com 800.784.4221
In a hurry?
Be sure to read pages
5-7 to ensure that
your Kestrel is setup
properly!
Revised 02/09

Kestrel®4000 Pocket Weather®Tracker
BACKLIGHT BUTTON Press
to activate backlight for
1 minute.
MODE BUTTONS
Press to change mode of
measurements: Current, Min/
Max/Avg, Chart.
COMMAND BUTTON In Chart
Screens, press to view data
points. In Setup Menus, press
to make selection.
MANUAL MEMORY
BUTTON Press to manually
store current conditions
to memory.
MEASUREMENT BUTTONS
Press to scroll between
screens: Date/Time,
Measurements, User
Dened Screens.
POWER/SETUP BUTTON
Hold to turn power on or
o. Press to enter and exit
Main Setup Menu.
FRONT

3
IMPELLER Sapphire jewel
bearings on a user-
replaceable impeller.
IMPELLER COVER Swivel
cover protects impeller
when not in use.
DATA UPLOAD OPTICAL
COUPLER Software and
serial port interface
sold separately.
BATTERY DOOR
Sealed with o-ring to
keep product watertight.
TEMPERATURE SENSOR
Hermetically sealed precision
thermistor coiled to isolate from
case temperature.
HUMIDITY SENSOR Capacitive
sensor with secondary
thermistor to improve
accuracy and response.
SERIAL NUMBER
PRESSURE SENSOR Monolithic
silicon piezoresistive sensor.
Do NOT insert any objects
into this hole.
AAA BATTERIES
BACK

Kestrel®4000 Pocket Weather®Tracker
TABLE OF CONTENTS
GETTINGSTARTED.....................................................................................5
NAVIGATION...........................................................................................6
SPECIALFUNCTIONS...................................................................................8
MAINSETUPMENU ...................................................................................13
APPLICATIONEXAMPLES..............................................................................18
MEMORYCAPABILITIES................................................................................21
GLOSSARY............................................................................................21
DEFAULTSETTINGS....................................................................................24
FREQUENTLYASKEDQUESTIONS......................................................................25
CUSTOMERSERVICE...................................................................................27
Congratulations on the purchase of your Kestrel 4000 Pocket Weather Tracker! The Kestrel 4000 is the next
generation of weather monitoring. Now, you can instantly measure EVERY major environmental condition
easily, accurately and right in the palm of your hand.
While the Kestrel 4000 is user-friendly and simple to use, reading the instruction manual is recommended in
order to use the Kestrel 4000 to its fullest potential.
NK, manufacturer of Kestrel Pocket Weather Meters, is available to answer questions and provide support.
Contact NK by phone: [phone], fax: [phone], email: [e-mail], or
web: www.nkhome.com.

5
GETTING STARTED
Pouch and Lanyards
A neck lanyard and wrist and a small pouch have been provided. To install the lanyard,
feed the thin end of the lanyard around the metal post on the battery door (as shown
in diagram). Feed the thick end of the lanyard through the loop on the thin end. Using
tweezers can help.
Battery Installation
Use only AAA batteries. Install batteries as indicated on the battery door. After installing the batteries, the
Kestrel 4000 will automatically start in the Date and Time Setting mode. (See Date and Time Setup below.)
Custom settings and chart data will be saved during a battery change; only the date/time and MMA values
will be lost.
Turning the Kestrel Meter ON and OFF
To turn the Kestrel Meter ON, press the button. To turn the Kestrel Meter OFF, hold the button for two
seconds. Or, press the button, then press the button with the word OFF highlighted. (Note: your unit
will continue to automatically store data when the power is turned o.) When rst turned on, the Kestrel
Meter will display a splash screen displaying the model number, the battery indicator, and the code version.
This battery indicator will indicate the percentage of battery life remaining, which is helpful in preventing
unexpected dead batteries.
Date and Time Setup
The rst time that you turn on your Kestrel Meter, as well as after a battery change, you
will need to set the date and time. The Introduction Screen will appear for 3 seconds,
followed by the Date/Time Setup Screen. Press the and buttons to scroll through
the settings. Press the and buttons to scroll through the setting options. After

Kestrel®4000 Pocket Weather®Tracker
entering the date and time, press the button to exit the Date/Time Setup. Then press the button
again to exit the Main Setup Menu.
NAVIGATION
Measurements use and
Wind Speed
Temperature
Wind Chill
Humidity
Heat Index
Dew Point
Wet Bulb
Barometric Pressure
Altitude
Density Altitude
The Kestrel 4000 is set up to display 10 Measurements (some are
calculations) in 3 Modes.
The Measurements are listed here with their corresponding screen
icon. In addition to these Measurements and Modes, there are also 3
User Screens, which simultaneously show 3 current measurements,
and the Date & Time Screen, which gives the current date and
time. Use the and buttons to scroll through the various
Measurements, followed by the 3 User Screens and the Date/Time
Screen. Any of these screens can be turned o so that you can
customize your Kestrel Meter to show the screens that your application
requires. (See the Measurements section in the Main Menu.)
The Modes are displayed below. Use the and buttons to scroll
through the various Modes. From any mode, you may still scroll to a
dierent Measurement by pressing the and buttons.
Current - Displays the instantaneous reading.
Min/Max/Avg - Displays the Minimum/Maximum/Average readings
from stored data. If there is no stored data, the values will be
displayed as --.-.
Chart - Displays a graphical representation of up to 2000 stored
data points for each measurement. If there is no stored data, the axis
will appear, but the chart will be blank. (See the following section
for information on Chart Navigation.)
HI
D
WB
DP

7
Modes use and
Navigation of Charts
The Kestrel 4000 is capable of storing up to 2000 data points for each measurement. To review the data,
press the button while viewing a chart. A cursor will appear on the most recent data point. Press the
and buttons to scroll through the data points. The date and time at which the data was stored will be
displayed at the bottom of the screen, and the data value will be displayed at the top of the screen. Hold
down the or button to scroll quickly through the data points.
Press the or button to review the data for the other measurements. Please note that the cursor will
remain at the same date and time. If new data is stored while viewing chart data, the entire chart will shift
left with the new data point charted on the right. The cursor will not shift with the chart.
Press the button to return to the Chart Mode.
Value
Chart
Cursor
Date & Time

Kestrel®4000 Pocket Weather®Tracker
SPECIAL FUNCTIONS
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 o. (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 aect 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 o and data log is full), or O (Manual Store button
has been disabled). (See the Main Setup Menu section for more information on memory.)

9
Backlight
The Kestrel Meter has a high-visibility green backlight, which makes the display easily read in low-light
conditions. The Kestrel 3500 NV has a night-vision preserving backlight which helps users to sustain natural
night vision. The NV’s backlight incorporates an optical lter to reduce overall brightness and minimize
blue and green spectrum light to preserve night vision. Additionally, the backlight is much dimmer than a
standard backlight, making it more dicult to detect with the naked eye in night operations. This backlight
appears soft greyish pink (not red) and is still in the visible spectrum, so it is not compatible with night-
vision equipment.
It takes 30 to 45 minutes for the average eye to adapt to darkness and maximize night vision. Even a short
burst of white, yellow, green or blue light “bleaches out” the rod cell photoreceptors in the eye and causes
night blindness until the entire adaptation process can take place again. Light in the red spectrum does not
cause this “bleaching out”, preventing night blindness and night vision fatigue.
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 specications, 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.

Kestrel®4000 Pocket Weather®Tracker
- Ideally, provide an airow of at least 1 M/S (2.2 MPH), over the temperature sensor—point the
Kestrel Meter into the airow. If there is no airow, simply wave the unit back and forth so air
passes over the sensors. With airow over the temperature sensors and humidity chambers,
readings within specications will be provided within two to three minutes, even after a large
temperature shift.
- If no airow can be provided, you must allow sucient 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 conrm 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 display of RH, and you can see when the value is no longer
changing signicantly. At that point, the RH value is stable and can be relied upon to be within the
accuracy specications.
Barometric Pressure and Altitude Adjustment
The Kestrel Meter measures “station” pressure—the actual air pressure in the measurement location—and
uses this value to calculate barometric pressure and altitude. Station pressure changes in response to
two things—changes in altitude and changes in the atmosphere. Because the Kestrel Meter is constantly
changing location and altitude, it is important to enter adjustments or“references” when accurate pressure
and altitude readings are needed.
Barometric pressure is station pressure corrected to sea level. In order to make the correction, the Kestrel
Meter needs an accurate reference altitude. Altitude is the height above sea level. In order to correctly
calculate altitude, the unit needs an accurate barometric pressure reference, also known as an “altimeter
setting”. Fortunately, you only need to know ONE of these values (current barometric pressure or current
altitude) in order to set your Kestrel Meter up to show accurate readings.

11
Starting with the known barometric pressure for your location: You can obtain your
current barometric pressure by checking an internet weather site for a nearby location,
or contacting a local airport. Set this value as your reference pressure on the ALTITUDE
screen to determine your correct altitude: Press the button to enter the reference
setting mode. Press the button to increase the reference pressure or the button to
decrease the reference pressure. You will notice that the altitude will change with changes in the reference
pressure. Press the button to exit the adjustment mode. Set your Kestrel Meter down on a table and
allow the altitude reading to stabilize. (Note: very small changes in pressure generate noticeable changes
in altitude. In order to provide meaningful readings for activities where altitude changes quickly, the Kestrel
Meter features rapid altitude response. This is why the altitude readings tend to uctuate by a few feet.)
After obtaining a current altitude from the ALTITUDE screen, move to the BARO screen and enter this value
as your reference altitude by following the same procedure. Both readings will now be accurate.
Starting with a known altitude for your location: You can obtain your altitude from a
topographical map or local landmark. Google Earth is an excellent free program that
provides the exact altitude for any given address: www.earth.google.com/. Set this
value as your reference altitude on the BARO screen to determine your barometric
pressure. Press the button to enter the reference setting mode. Press the button
to increase the reference altitude or the button to decrease the reference altitude. You will notice that
the barometric pressure will change with changes in the reference altitude. Press the button to exit the
adjustment mode. Again, allow the Kestrel Meter to stabilize, then enter the value from the BARO screen
as your reference pressure on the ALTITUDE screen by following the same procedure. Both readings are
nowaccurate.
When reviewing stored data, remember that changes in pressure AND changes in location/altitude will
aect the stored values. When tracking pressure changes relative to weather, set the reference altitude on
the BARO screen and keep the Kestrel Meter in one location. Your graph history will now show trends in

Kestrel®4000 Pocket Weather®Tracker
barometric pressure. Your altitude as shown on the ALTITUDE screen will change as the weather changes,
but you can ignore this screen for this purpose.
If you are planning a day hike would like to track your altitude, you’ll need to enter the correct reference
pressure on the ALTITUDE screen as described above in “starting with the known barometric pressure.”
You can now track the altitude changes as you hike. In this instance, you should ignore the values on the
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 aect the accuracy of the altimeter over time. This is why aircraft reset their altimeters
at every aireld by entering the eld’s “altimeter setting”or reference pressure. Accordingly, if accurate
altitude readings are your primary interest, you should reset the reference pressure on your Kestrel Meter
regularly. If you encounter an elevation landmark, you can adjust the reference pressure until the altitude
matches the landmark elevation. This will correct the altitude for any pressure changes due to the weather.
(Or, you can obtain an updated reference pressure from the sources described above.)
Some nal notes - If you wish to know the actual or station pressure for your location (such as for engine
tuning), simply set the reference altitude on the BARO screen to“0”. In this case, the Kestrel Meter will
not make any adjustment and will display the measured value. (Engine tuning and ballistics software
sometimes refer to atmospheric or station pressure as“absolute pressure.” These applications are
concerned with the actual air density, as opposed to pressure gradients relating to weather, so barometric
pressure is less useful.)
Also, the above discussion applies to ALL pressure altimeters, including one you may have in a watch or
other device, but not to GPS altimeters, which use satellite triangulation to determine altitude. Note that
with present GPS technology, pressure altimeters remain more accurate for measuring altitude change. This
is why airplanes still rely on pressure altimeters, not GPS.

13
Finally, the DENSITY ALTITUDE screen is calculated from the absolute values of station pressure,
relative humidity and temperature, and is not aected by the reference values entered in the BARO and
ALTITUDE screens.
MAIN SETUP MENU
You can customize your Kestrel Meter in multiple ways. Press the button to access the Main Setup Menu.
Press the button to select the highlighted setting. The Main Setup Menu contains: OFF, Memory Options,
Measurements, Graph Scale, Units, User Screens, System, Date & Time, Language and Restore.
O
Press the then the button to turn the display o. Even when the Kestrel Meter’s display is turned
o, the unit will continue to automatically store data at the dened Store Rate. The battery life will be
decreased if data is stored frequently. The only way to completely shut o the unit is to remove the
batteries. Custom settings and data will be stored when the batteries are removed.
Memory Options
These settings control the data storage properties.
Setting Description Operation
Clear Log
(Go/Done)
All stored data is cleared. This will also clear
Min/Max/Avg data.
Press or to clear the log.
Reset MMA
(Go/Done)
All Min/Max/Avg data is cleared. Chart data
will remain intact.
Press or to clear the MMA.

Kestrel®4000 Pocket Weather®Tracker
Auto Store
(On/O)
When On, data is automatically stored at
preset Store Rate. When O, data is only
stored when manually captured with the
button.
Press or to toggle between
On and O.
Store Rate*
(2 sec – 12 hr)
The frequency at which data sets are
automatically stored. (Battery life may be
shortened if data is stored frequently.)
Press or to increase or
decrease Store Rate frequency.
Overwrite
(On/O)
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 O, new data points are
not saved.
Press or to toggle between
On and O.
Man Store
(On/O)
When On, data is stored when the
button is pressed. When o, the button is
disabled.
Press or to toggle between
On and O.
* When unit is o, data is NOT stored for 2 sec and 5 sec Store Rates.
Measurements
Measurement screens can be turned o, or “hidden” from the normal measurement navigation. For
example, if wind chill is not of interest, it can be hidden. Press the or button to toggle between ON
and OFF for each individual measurement. Press the or button to highlight the desired measurement.
Press the button to return to the Main Setup Menu. Even when measurements are hidden, the Kestrel
Meter will continue to log data for all measurements. If you wish to see the logged data for measurements

15
that are hidden, simply enter the Measurement screen and turn them back on. The data will be stored in the
same manner as all other measurements, as specied in the Store Rate.
Graph Scale
These settings control the chart limits of your Kestrel Meter. Depending on the conditions, the lower and
upper limits of the chart scale may need to be adjusted in order to get the best view of the data. Highlight
the desired measurement by pressing the or button. Select the highlighted measurement by
pressing the button. Press the or button to increase or decrease the value of the limits. Press the
or button to change between the upper and lower limits. Press the button to exit and return to the
Measurement Selection screen. Press the button to return to the Main Setup Menu.
Wind Speed Temperature, Dewpoint,
Wet Bulb Temp, Wind Chill &
Heat Index
Pressure Altitude,
Density
Altitude
m/s meters per second
km/h kilometers per hour
kt knots
mph miles per hour
ft/m feet per minute
Bft Beaufort
°C Celsius
°F Fahrenheit
InHg inches
mercury
HPa hectopascals
psi pounds per
square inch
mb milibar
m meters
ft feet

Kestrel®4000 Pocket Weather®Tracker
Units
The units of measure can be adjusted to best suit the application. The following units are available:
Highlight the desired measurement by pressing the or button. Press the or button to scroll
through the available units. Press the button to return to the Main Setup Menu.
User Screens
The three User Screens can be recongured 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.
From the Main Setup Menu, highlight the desired User Screen by pressing the or button. Press the
button to select the highlighted User Screen. Press the or buttons to change lines, and the or
button to scroll through the available measurements for each highlighted line. Press the button to
return to the User Screen Setup Menu. Repeat above process for the other User Screens or press the
button to return to the Main Setup Menu. The User Screens may also be hidden if not needed.
System
The display Contrast and Auto Shutdown can be recongured as required. The relative humidity and
pressure sensors can also be recalibrated. Press the or buttons to highlight the appropriate selection,
and the or button to adjust or select.
The Contrast can be adjusted for better visibility depending on the ambient lighting conditions. Press the
or button to increase or decrease the contrast from 0 to 20 (0 is lightest, 20 is darkest).
The display can be set to automatically turn o in order to conserve the battery life. Auto Shutdown will
only occur after the preset time has elapsed without any button presses. Press the or button to scroll
through the Auto Shutdown options (15 minutes, 60 minutes, O). Battery life will be shortened if the Auto
Shutdown is turned to O.

17
Baro Cal - Recalibration of this sensor is not typically required, and it is not recommended that you recalibrate
without speaking to an NK technician. The pressure sensor can be calibrated if necessary. It is extremely
important to know the precise altitude and mean sea level barometric pressure at the time of calibrating
the sensor. First, set the reference altitude on the BARO measurement screen to the known altitude (see
Pressure Adjustment section for instructions). Then adjust the calibrating setting on the Baro Cal screen to
the known mean sea level barometric pressure. If recalibration is desired, the unit may also be returned to
NK for service.
Humidity Cal - Recalibration of this sensor is not typically required, and it is not recommended that you
recalibrate without speaking to an NK technician. The humidity sensor can be calibrated by“teaching”it
the correct humidity. Some special equipment is required for this calibration, including two hermetically
sealed containers and saturated salt solutions. NK oers a calibration kit, and instructions are available
on www.nkhome.com. If recalibration is desired, the unit may also be returned to NK for service.
Date & Time
The date and time, as well as date and time formats, can be adjusted. The Time Formats available are 12
hour and 24 hour. The Date formats available are day/month/year and month/day/year. (See the Date and
Time Set Up section for instructions.) Press the button to return to the Main Setup Menu.
Language
Displayed text can be set in one of ve languages: English, French, German, Italian or Spanish. To choose
a language, use the or buttons to highlight the desired language. Press the button to select the
language and return to the Main Setup Menu. Otherwise, press the button to return to the Main Setup
Menu without changing languages.
Restore
Default settings for units of measure, date and time formats, and system settings can be restored. (See the
Factory Default Settings section for more information.) Press the or button to highlight the desired

Kestrel®4000 Pocket Weather®Tracker
default setting: Metric, Imperial or Defaults. Press the or button to reset the factory setting. Press the
button to return to the Main Setup Menu.
APPLICATION EXAMPLES
This section provides examples of applications where a Kestrel Meter might be used, and the appropriate
memory settings.
Weather Monitoring
Auto Store On
Store Rate 1 hr
Overwrite On
Man Store O
These settings will allow you to track conditions for 2 months. When the memory is full, each new
measurement will be stored in place of the oldest data point. The charts will provide a quick look at the
recent weather conditions. Keep an eye out for falling barometric pressure, which indicates that a storm
is coming.
Hiking/Camping for the Weekend
Auto Store On
Store Rate 20 min
Overwrite O
Man Store On
These settings will allow you to track the conditions for almost 20 days. Measurements will be stored every
20 minutes, and stop storing when the log is full. This will let you review the trip at your convenience when
you return. You can also manually store the conditions, in case you get caught in 40 mile per hour winds or

19
make it to the top of a mountain. For more detailed information on your trip, set the Store Rate to 2 hours
overnight, and 10 minutes during the day.
Soaring/Hang Gliding
Auto Store On
Store Rate 2 min
Overwrite O
Man Store On
These settings will allow you to track all conditions for 46 hours. Chart your altitude changes, watch how
the temperature and humidity vary with altitude, and log your apparent speed. Data will no longer be
stored once the log is full, in order to preserve it until it can be reviewed later. Be sure to clear the data log
just before your ight.
Skydiving
Auto Store On
Store Rate 2 sec
Overwrite O
Man Store O
These settings will allow you to record a detailed account of your jump. Be sure to clear the data log just
before jumping. As you descend toward the ground, you will be tracking the altitude every two seconds, as
well as the conditions at that altitude. The chart will clearly show the point at which the parachute opens, as
well as the point you get back on the ground.

Kestrel®4000 Pocket Weather®Tracker
HVAC - Environmental Monitoring
Auto Store On
Store Rate 5 min
Overwrite On
Man Store O
These settings will record conditions every ve minutes, for a total storage of almost 2 days. You can
monitor the conditions in a laboratory or manufacturing plant, both day and night, to determine if the
climate control is working properly. Or you can examine the eect on the environment when employees
enter and exit the building.
HVAC/R - System Balancing
Auto Store O
Store Rate —
Overwrite O
Man Store On
These settings will require you to press the Manual Store Button in order to store any data at a duct, hood,
vent, or other air system. The meter will not store any data automatically. Be sure to record the location and
date/time of storage for reference when reviewing the data. After storing the conditions at each location,
simply review the data and balance the system.