Kestrel 3500 Delta T User Manual

NKhome.com

Weather & Environmental Meters

I NS TR UC TI ON M AN UA L

1 0 00 , 20 0 0 , 2 5 0 0 & 2 50 0 N V,

3 0 00 , 35 0 0 & 3 5 00 N V , 3 5 0 0D T

1

OVERVI EW

CAUTION

!

Your Kestrel brand Weather Meter is designed to provide accurate measurement of current conditions

only. Depending on your location and environment, conditions may change rapidly.

Rapid temperature and humidity changes (ie moving your meter from indoors to outdoors) may cause inaccurate readings of temperature and humidity
as well as all readings that rely on either of these values. Before relying on Kestrel Weather Meter readings, use care to either a) force air ow over the
sensors by waving or slinging your meter through the air; or b) wait until your unit’s readings have stabilized, indicating it has equilibrated to its new
environment.

To maximize the accuracy and reliability of your readings:

• Ensure that your Kestrel Meter is in good repair and within factory calibration.

• Take readings frequently and carefully according to the guidelines above.

• Allow your meter’s readings to stabilize after signicant changes in temperature or humidity (ie changing location from indoors to outdoors).

• Allow a margin of safety for changing conditions and reading errors (2-3% of reading is recommended).

Use extra care and good judgment when referring to your Kestrel Weather Meter to make any

decisions regarding safety, health or property protection.

Features & Options.................................................................4

Getting to Know Your Kestrel...............................................5

Getting Started.......................................................................6

Setup + Options......................................................................6

Barometric Pressure & Altitude Adjustment....................7

Measurement Notes..............................................................8

Maintenance & Service..........................................................9

Sensor Calibration...............................................................10

NK, manufacturer of Kestrel Weather Meters,
is available to answer questions and provide support.
Contact NK by phone: [phone]; fax: [phone];
email: [e-mail]; or web: NKhome.com.

2 3

FEATURES & OPTIONS

GETT ING TO KNOW YOUR KESTREL

The table below shows all Measurement screens available, listed with their
corresponding screen icon and “Hint” abbreviation.

Measurement Icon Hint Units of Measure 1000 2000 2500 3000 3500 3500DT
Wind Speed SPd mph | kt | B | m/s | ft/min | km/h • • • • • •
Temperature dEG ˚F | ˚C • • • • •
Wind Chill chill ˚F | ˚C • • • •
Relative Humidity % r.h. % • • •
Heat Stress Index % H.I ˚F | ˚C • •
Dewpoint Temp d.P. ˚F | ˚C • • •
Barometric Pressure bAro inHg | hPA | mb • • •
Altitude Alt m | ft • • •
Wet Bulb Temp bulb ˚F | ˚C • •
Backlit Display • • • • •
Pressure Trend • •
Delta T dElt •
Clock • • •

*The NV series features a dim red backlight for use in low or nighttime situations.
*Only one arrow icon will be displayed on screen to indicate the 3-hour pressure trend.

TEMPERATURE

THERMISTOR

(N/A on K1000)

POWER/BACKLIGHT

(Backlight N/A on K1000)

BUTTON

FRONT

3000

REPLACEABLE
IMPELLER

NAVIGATION
BUTTONS

PRESSURE

SENSOR

SERIAL

NUMBER

HUMIDITY

SENSOR

BACK

Nielsen Kellerman

www.nkhome.com
[e-mail]

610.447.1555

US Patents
5,783,753
5,939,645

BATTERY DOOR:
CR2032 COIN CELL

*All Kestrel Meters with temperature measurment allow you to measure air, water and snow temperature.

4 5

GETT ING STARTED

Turning ON and OFF

• Press to turn on.

• Hold for 3 seconds to turn o.

The Kestrel Meter will automatically turn o if no buttons have been

pressed for 45 minutes.

Select Measurement Mode

• Use or to access each Measurement screen

• The instantaneous Measurement value will be displayed
on each screen and updated once per second.

Each Measurement screen will ash a brief “Hint” to clarify which
Measurement is being displayed. Note: Hints are not displayed in the
Kestrel 1000.

The Measurement’s icons and units of measure will be displayed in the
lower line of the screen.

75.2

Temperature “Hint”

ashes before

°F °F

Temperature

Measurement Screen

SETUP + OPTIONS

Select the Unit of Measure

• Select the unit of measure. While holding , press
to scroll through the available units of measure for that
measurement.

Adjust the Clock

*This applies to the 2500, 2500NV, 3500, 3500NV and 3500DT.

• Adjust the clock. Simultaneously press and
to access clock setting. While the time is blinking,
press or to change the time. Hold either
button down to adjust quickly. Simultaneously
press and to exit clock setting.

BAROME TRIC PRESSU RE & ALTITUDE ADJUSTM ENT

SETTING REFERENCE BAROMETRIC PRESSURE &
ALTITUDE: KESTREL 2500 & KESTREL 3500 ONLY

The Kestrel Meter measures “station pressure,” which changes in
response to both changes in altitude and changes in atmosphere.
Barometric pressure is a measurement of the air pressure adjusted to
sea level. To obtain accurate barometric pressure and altitude

readings, you must rst enter EITHER your location’s current
barometric pressure OR your current altitude.

*Station pressure is displayed if the reference altitude is set to zero.

Starting with Known Altitude for your Location

• Use or to highlight the “BARO” screen.

• Press and simultaneously until the word “REF”
starts blinking on screen.

• Use or to adjust the value to the correct known
Altitude.

• Press and simultaneously to exit the reference
setting mode.

After the Altitude reference is set, place the unit on a table and allow
it to stabilize. The accurate Barometric Pressure reading will then be
displayed on screen.

Note the correct barometric pressure reading
above and use this measurement to set the

Altitude:

• Use or to highlight the “Altitude” screen.

• Press and simultaneously until the word “REF”
starts blinking on screen.

• Use or to adjust the value to the barometric
pressure measurement noted above.

• Press and simultaneously again to exit the
setting mode.

Starting with Known Barometric Pressure for your
Location

• Use or to highlight the “Altitude” screen.

• Press and simultaneously until the word “REF” starts
blinking on screen.

• Use or to adjust the reference value to the correct
known Barometric Pressure.

• Press and simultaneously again to exit the setting
mode.

After the Pressure reference is set, place the unit on a table and allow
it to stabilize. The accurate Altitude reading will then be displayed
on screen.

Note the correct altitude reading above and use this to
set the Barometric Pressure:

• Use or to highlight the “BARO” screen.

• Press and simultaneously until the word “REF” starts
blinking on screen.

• Use or to adjust the reference value to the correct
known Altitude.

• Press and simultaneously again to exit the
setting mode.

Once these steps are complete, both screens will display
accurate readings.

*Be sure to adjust your reference measurements when you change your
location for altitude and/or barometric pressure or when there has been
dramatic change in weather conditions.

6 7

MEASUREMENT NOTES

CAUTION

!

•

MAINTENANCE & SE RVICE

MEASUREMENTS

Barometric Pressure Trend

: indicates pressure is rising quickly (> +0.18 inHg) in 3 hours
: indicates pressure is rising (within +0.06 and +0.18 inHg)
: indicates pressure is stable (remains between -0.06 and +0.06 inHg)
: indicates pressure is dropping (within -0.06 and -0.18 inHg)
: indicates pressure is falling quickly (> -0.18 inHg)

Select Units of Measure

• Use or to scroll to the desired Measurement
screen.

• Hold down , then press to set the desired Units of
Measure for the Measurement.

Water and Snow Temperature

The Kestrel Meter may also be used to measure the
temperature of water and snow. Submerge the thermistor
portion (curly exposed wire in window next to
impeller) in water or snow to get an accurate reading.
Kestrel Meters are completely waterproof, oat and can be
safely submerged in water according to IP-67 standards
(up to 1 meter for a maximum of 30 minutes).

Max/Avg Function

To view the maximum wind gust recorded, press or

until you see “MAX” appear at bottom of screen. Press
again to view average wind gust. “AVG” will appear at
bottom of screen. Both Max and Average are reset each
time the unit is powered down. To restart averaging,
simply turn the unit o and back on again.

8

Hold Mode

Hold Mode can be useful for taking measurements when you are

unable to view the display.

• Hold down , then press .

• The word “HOLD” will blink on each screen and all values
will stop measuring and freeze in memory.

• Use or to view each Measurement screen in Hold
Mode.

• To exit Hold Mode, hold down , then press again.

Backlight*

• Press to activate the backlight for 10 seconds.

• Press again to manually deactivate the backlight
before 10 seconds expire.

*The Kestrel 1000 Meter does NOT oer a backlight.

MAINTENANCE & SERVICE

Replacing the Battery

When your display becomes dim or disappears, you need to
change the battery.

Use a US nickel or similar coin to twist open the battery
compartment.

Replace battery with a new, clean CR2032 coin-cell battery,
with positive side (+) facing up.

CR2032 batteries are available in most stores that sell
batteries.

When replacing the battery door, be sure to keep the black rubber o-ring

seated in the groove on the case back.

CR2032 batteries contain lithium, a toxic substance. Ingestion may cause serious injury or death. Keep battery
out of the reach of children. If swallowed, immediately seek medical help. Have doctor phone 24-hour hotline
at [phone], call collect if necessary. Dispose of batteries properly and according to local regulations. Do
not puncture or burn batteries.

9

SENSOR CALIBR ATION

Impeller

The Kestrel impeller calibration drift is less than 1% after
100 hours of use at 16 MPH | 7 m/s. Drift increases with
higher-speed use. For most users, the impeller will provide
accurate wind speed/air ow readings for years if not
physically damaged. However, if your application requires
extremely high precision or if you perform frequent
high-speed readings, we recommend you replace your
impeller at one-year intervals. Every replacement impeller
is supplied with a certicate of conformity and restores your
Kestrel’s calibration upon installation.

Temperature Sensor (Kestrel 2000 and higher)

The Kestrel temperature sensor exhibits virtually zero drift
over time and generally does not require recalibration for
accurate performance during the life of the product. If your
industry or application requires calibration, please contact
NK or a certied calibration lab for options and pricing.

Humidity Sensor (Kestrel 3000 and higher)

The Kestrel humidity sensor calibration drift may be up to
+/- 2% over 24 months. For high-precision applications,
we recommend recalibration at 24-month intervals. If you
require calibration, please contact NK or a certied
calibration lab for options and pricing. The humidity sensor
may also be recalibrated in the eld using a Kestrel
Humidity Calibration Kit (NK PN-0802). Instructions for
running the recalibration routine are provided with the
Humidity Calibration Kit and may also be found at

http://www.nkhome.com/support/instructions/cali_kit_07.html.

10 11

Pressure Sensor (Kestrel 2500 & 3500)

The Kestrel pressure sensor drift may be up to 1 mbar
over 12 months. For high-precision applications, we
recommend recalibration at 12-month intervals. If you
require calibration, please contact NK or a certied
calibration lab for options and pricing. The pressure sensor
may also be recalibrated in the eld with reference to a
known-accurate and calibrated pressure standard. We do
not recommend simply recalibrating to a local weather
station as this may not be accurate for your location.
Instructions for recalibrating the pressure sensor may be
found at www.nkhome.com/kestrel/user-guides/
calibration_eld.php.

5-YEAR L IMITED PRODUCT WARRANTY

WARRANTY CERTIFICATE

Your Kestrel Weather Meter is warrantied to be free of defects in materials and workmanship for a period of FIVE
YEARS from the date of its rst consumer purchase. NK will repair or replace any defective meter or part when
notied within the warranty period, and will return the meter via domestic ground shipping or NK’s choice of
method of international shipping at no charge. The following are excluded from warranty coverage: damage
due to improper use or neglect (including corrosion); damage caused by severe or excessive impact, crushing
or mechanical harm; modications or attempted repairs by someone other than an authorized NK repair agent;
impeller failure not caused by a manufacturing defect; normal usage wear; failed batteries; and accuracy issues
resolvable by recalibration. If no warranty registration or proof of purchase is provided, the warranty period will be
measured from the meter’s date of manufacture.

Except for the warranties set forth herein, NK disclaims all other warranties, expressed, implied or
statutory, including, but not limited to, the implied warranties of merchantability or tness for a particular
purpose. Any implied warranties that may be imposed by applicable law are limited to the term of this
warranty. In no event shall NK be liable for any incidental, special or consequential damages, including,
but not limited to, loss of business, loss of prots, loss of data or use, whether in an action in contract
or tort or based on a warranty, arising out of or in connection with the use or performance of an NK
product, even if NK has been advised of the possibility of such damages. You agree that repair, and (upon
availability) replacement, as applicable, is your sole and exclusive 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.

NIELSEN-KELLERMAN
21 Creek Circle, Boothwyn, PA 19061
Phone: [phone]
Fax: [phone]
Web: NKhome.com
Email: [e-mail]

Please register your Kestrel Meter at NKhome.com NK#9012_0_13.2.5

12

Kestrel® Weather & Environmental Meters are
designed & manufactured in the U.S.A.