IR- Kestrel 3500 Wind Meter - Gail S.
- Here is my IR for the Kestrel 3500 Pocket Wind Meter.
I have having so much fun with it already :)
(I apologize if this shows up more than once..my Yahoo
mail has been bouncing repeatedly)
Kestrel 3500 Pocket Wind Meter
by Gail Staisil, Marquette, Michigan
October 28, 2006
Name: Gail Staisil
Height: 5' 9" (1.75 m)
Weight: 140 lb (64 kg)
Location: Marquette, Michigan USA
For the last 17 years, backpacking has become a
passion. I am a four-season backpacker and an
off-trail navigator. Although I do take yearly trips
to the American West or Southwest, the majority of my
trips are in Michigan and Canada. My pack weight
varies considerably but my base weight is below 18 lb
(8 kg). I am primarily a tarp camper who averages more
than 50 nights a year backpacking in a huge variety of
weather conditions including relentless rain, wet snow
and sub-zero temps.
Kestrel 3500 Pocket Wind Meter-- Description
Model Kestrel 3500 Pocket Wind Meter (Made in the USA)
Plastic case and unit, Hermetically-sealed
thermistor, Plastic wind repeller with sapphire
bearings, Polymer capacitive humidity sensor,
Monolitic Silicon Piezoresisitive sensor (measures
pressure), CR2032 battery
Unit Size with cover
4.8 in X1.75 in X 0.7 in
(12.19cm X 4.45 cm X 0.18 cm)
Manufacturer's Weight for unit with cover
3.6 oz (102 g)
Tested Weight for unit with cover
3.5 oz (99 g)
Model Year 2006
MSRP $249.00 US
The Kestrel 3500 Pocket Wind Meter is a portable
weather instrument that measures every common
environmental condition. It is one in the line of many
different wind meters produced by the company of
Nielsen-Kellerman. The wind meter is not only both
waterproof and features a real-time clock, but it also
includes a backlight, a protective cover, a lanyard
with cordlock, a battery and a two-year warranty. The
wind meter can measure the following:
Function or Mode
Current Wind Speed
Measures the average wind speed over the previous
Maximum Wind Speed
Measures the maximum 3-second wind speed since the
meter was turned on.
Average Wind Speed
Average wind speed since the meter was turned on.
Instant temperature reading - For a fast response,
hold the meter into the wind or wave the meter from
side to side-Temperatures should be taken in the
Water and Snow Temperatures
These temperatures can be taken by holding the meter
in water or snow.
It is the combination of wind speed and temperature
as defined by the US National Weather Service. The
calculation takes into consideration the effects of
combined wind and temperature on the human body and
animals. Wind Chill readings are the same as
temperature ratings above 45 F (7 C) or below 3 MPH.
Measures the amount of moisture in the air compared
to the mound of moisture the air can hold for the
given temperature (Percentage reading). Should be
measured in the shade.
It is calculated based on temperature and humidity
measurements as a measure of moisture in the air. If
the dewpoint is very close to the temperature, the air
is humid. If the temperature equals the dewpoint, dew
will form above freezing and frost below freezing.
Heat Stress Index
Measures the combination of temperature and humidity
as defined by the US National Weather Service. That
calculation takes into consideration how the
temperature feels to the human body and animals. Heat
stress readings are the same as temperature readings
below 70 F (21 C).
A reference value for barometric pressure must first
be obtained from a local weather station for the
current value of barometric pressure. It must then be
set as the reference pressure on the ALTITUDE screen
of the unit. The meter uses an atmospheric pressure
sensor and then calculates altitude based on a
standard atmosphere. The pressure trend is constantly
updated over a 3-hour period.
A reference value for altitude should be obtained
from a topo map. It can then be set as the reference
altitude on the BAROMETRIC PRESSURE screen of the
Wet Bulb Temperature
It is calculated based on temperature and humidity
measurements, as a measure of evaporation rate. If the
wet bulb temperature is very close to the air
temperature the air will be humid.
Warranty (per website):
NK does not believe in "disposable electronics." We
know our products don't lead a pampered life, and we
design them for years of performance in tough
conditions. We guarantee every NK product to be free
of defects in materials and workmanship for a period
of TWO YEARS from your date of purchase. We will
repair or replace any defective product or part when
notified within the warranty period, and will return
the product via domestic ground shipping at no charge.
The following issues do not result from a
manufacturing defect and are not covered under this
* Damage due to improper use or neglect (including
* Impact damage
* Modifications or attempted repairs by someone
other than an authorized NK repair agent
* Impeller failure not caused by a manufacturing
* Normal wear from use of the product
* Failed batteries
* Re-calibration beyond 30 days from your date of
Kestrel 3500 Pocket Wind Meter--
The Kestrel 3500 Pocket Wind Meter arrived at a great
time of year for monitoring the abruptly changing
weather conditions. I was a bit apprehensive about
whether I would understand how to use the meter, as
technical gadgets usually have quite a learning curve
for me. I'm usually resistant to reading manuals as I
find many of them rather confusing. However, this one
didn't appear intimidating. In fact, the manual is
just a single sheet of two-sided legal-size paper. It
is exactly the same information as I viewed on their
website's PDF file before I received the unit. It
contains operational, maintenance and warranty
instructions. In addition, there is a chart on
specifications and definitions of measurements. It was
easy to understand. The wind meter came with a
Certificate of Conformity that assures that the wind
meter met the specifications that are listed on the
backside of the certificate. It also lists the methods
used in calibration and testing.
In addition to the manual and certificate, the wind
meter was sent with a matching case, an attached
lanyard with cordlock, and a pre-installed battery.
Since I doubt I would ever take the wind meter on any
my trips without the case, I immediately took off the
cordlock on the lanyard, and threaded the lanyard
through the large oval slot on the bottom of the case.
I inserted the wind meter into the large opening in
the top of the case and then reattached the cordlock.
The cover slides over the meter providing protection
so that the exposed wind impeller and temperature
sensor will be protected from other objects in my
pack. The wind meter is already waterproof so the
cover only protects the front and back of the unit
from sharp objects.
The wind meter looks exactly like I expected it to
after I initially viewed it on the website. It is both
small in size and very lightweight. In fact, the unit
by itself without the case, was measured by myself to
be only 2.2 oz (62 g). I'm still not sure why it is
called a wind meter when it measures so much more than
wind. However, the wind meter does belongs to NK's
larger group of products classified as weather meters.
The front side of the meter looks very simple. The
wind-measuring impeller is inserted into the top of
the unit. It is circular in shape with a diameter of 1
in (2.54 cm) and it pivots on sapphire bearings. It
looks like the blades of a household fan. It moves
quite freely even when gently handling the unit. To
the left and beneath the wind impeller is an opening
that was molded into the unit. It contains the
temperature sensor. The temperature sensor is outside
the case unlike many other temperature devices. This
helps to ensure that the sensor is actually measuring
the temperature and not being affected by body heat
from my hands or even the case itself. This sensor
actually looks like a curled double-strand wire.
Humidity is measured by the patented dual temperature
sensor configuration. In the center of the front of
the unit is the viewing screen and below that are
located the three operational buttons. The viewing
screen has an Aviation Green backlight that can be
activated when needed and the display has easy-to-read
digits that are 0.36 in (9mm) in height.
The back of the unit is similar in that I can see both
the wind impeller and temperature sensor.There is an
inserted "cheat sheet" that tells me what the function
of each of the three buttons on the front are used for
and also which button turns on the backlight. Beneath
the center on the meter's back, the plastic is
ergonomically molded to provide a place for my index
finger to rest while my thumb rests on the lower half
of the front of the unit. The lower half of the
backside of the unit contains the battery case that is
about 1.125 in (2.86 cm) in diameter. On the outside
of the battery cover, it is scripted with the name of
the battery required for the unit (CR2032 battery).
That is very cool as I dislike having to take any
gadget apart to find out what kind of battery I need
to buy. The cover also is grooved so that the cover
can be rotated and removed. A battery was already
pre-installed in the meter so I only need to obtain a
back-up one for the future.
My instinct was to follow the ten quick steps to
operate the unit. The meter itself has only three
buttons. I like that. I also had to familiarize myself
with the icons for the different functions that are
indicated in the manual. In brief, the following 10
steps are suggested (I simplified them a bit and added
1. Slide off cover - Easy enough!
2. Turn on - Press center button. No wait time.
3. Select measurement - Use right arrow to scroll
though measurements, left arrow to reverse. The
measurement is preceded by a brief hint to let me know
what measurement is being displayed and then it is
displayed instantly. I found that these measurements
were easy-to-see without reading glasses as the
digits are 0.36 in (9 mm) in height. The hints were
invaluable for a first-time user.
4. Select the unit of measure - Hold down center
button and scroll with right arrow (it scrolls through
the measurements. I had to change all of them to get
to my preferred unit of measure such as " F" for
temperatures and " ft" for distance). The wind meter
alone had 6 different choices for the unit of measure
but I chose the one that I am most familiar with for
now (MPH).This will be very convenient to get an
instant conversion for BGT reports. I also spend a lot
of time in Canada where the units are different than
the States. The unit of measure is hard to read
without glasses as the letters are only about 0.04 in
(1 mm) in height.
5. Hold mode - Press and hold center button and press
left button to hold time and all measure values. Their
is a hold indicator that blinks while it is in that
mode. To reverse, hold the center button and press
left button. This is handy for taking measurements
when unable to view the display.
6. Turn on the backlight - Press center button to
activate for 10 seconds. Press either the right or
left arrow and it will add another 10 seconds. Press
center button to turn off the display.
7. Adjust the clock - Press both left and right
arrows at the same time. The clock should blink and
then use right or left arrow to change the time.
Holding down the arrow will change the time faster.
Press down both arrows to lock in the time.
8. Adjust the reference altitude - Use a local
landmark or topo map for correct measurement of
altitude. Use barometric pressure screen and then
press both arrow buttons to adjust the display. Press
either arrow to adjust the altitude (holding either
arrow will change it faster). Press both arrows
together to exit.
9. Adjust the reference pressure - Use a barometric
pressure reading from a local weather source. From the
altitude screen press both arrows to adjust the
display. Press either arrow to adjust the pressure
(holding either arrow will change it faster). Press
both arrows together to exit.
10. Turn off - Hold the center button for 2 seconds.
The unit automatically turns off if it hasn't been
used for 45 minutes.
Shortly after I finished setting up the wind meter
with my preferred units of measurement, I took it out
on a hike near Lake Superior. It was quite a windy day
and it was loads of fun to scroll through all the
different measurements. Most of the measurements
update every second but I could lock in the values by
using the hold mode. I have never cancelled a trip due
to bad weather, but I'm already wondering how I ever
got along without having such ready access to valuable
weather data. I have always been interested in
monitoring the weather since I took a college course
years ago, but I had never used a technical meter. I
can hardly wait to take it on a backpacking trip later
this week and monitor the weather for the four-day
* Lanyard and case make it easy to transport
* The numbers on the unit are easy to see
* Easy to operate
* Small letters for the units of measure - I may
need to wear glasses to change units
Kestrel 3500 Pocket Wind Meter-- Test Plan
My scheduled fall and winter backpacking trips in
Michigan include a four-day trip to the Hiawatha
National Forest in November, a four-day trip to the
Pigeon River State Forest in December, a five-day
winter sledge trip in January to Michigan's Eastern
Upper Peninsula, and a nine-day winter sledge trip in
February to Ontario, Canada. In addition, I am very
prone to taking last-minute trips. I also plan to use
the weather unit locally to monitor snow conditions
for cross-country ski training sessions. The humidity
and snow temperature functions will be used to to
evaluate wax selection for my skiis. I anticipate
maximum usage for a wide variety of outings.
The next four months in the Great Lakes area of
Michigan and Canada will produce many wild, windy,
rainy and snow-filled days and nights. The Great Lakes
create their own unique weather system, so I would
expect rapid sudden drops in temperatures and much
precipitation in the form of rain and snow during this
time period. The testing conditions will be at low
elevation or low altitude 600 ft (183 m) to 2000 ft
(610 m), with mostly cold conditions and mid-to-high
range humidity (50-100 percent).
Testing location temperatures in Michigan will range
from the average low in January of 3F (-16C) to the
average high of 35 F(2 C) in December. These are only
averages, I have been on several trips where the
temperatures dipped to a low of -20F (-29C) in January
and a foot or more of snow has fallen in a short
amount of time. Average precipitation for the Michigan
trips is approximately 13 in (33cm) during this time
period, however average snowfall for the winter totals
at least 185 in (470 cm) in some of the areas that I
will be camping.
My February trip to Ontario, Canada could produce lows
of -40F (-40C) with the average low being -19 (-2F) In
addition, snowfall for the month of February averages
21 in (54 cm) with an average snow depth of 26 in (67
cm). Again, this is an average, there is frequently
over 6 ft (1.83 m) of snow on the ground during the
All of these trips will be taken to hilly boreal or
deciduous forests. Most of the trips planned are of
the bushwhack variety, so in addition to the above, I
will also be traveling across flat, frozen, windy
lakes during the January, and February trips.
I will test the Kestrel 3500 Pocket Wind Meter with
the following considerations in mind:
Ease of Use:
-Will the Kestrel unit be easy to use after studying
the manual or will it be intuitive? Because the manual
was so short, I decided to read the short steps and go
from there. Most of it would of been intuitive but it
surely cut down the guess factor.
-Will I need to wear glasses to read the display or
will the numbers be large enough to view without them?
No glasses for me. The small unit measurements are
harder to see so if I decided to switch those, I'd
probably need my glasses.
-Will the backlight provide additional help to view
the numbers in daylight conditions as well as in
-Will the wind meter store information automatically
so that I can view it later or do I need to operate it
each time I want a reading?
-Will I easily be able to switch display modes without
frustration? So easy.
-Will the unit have to be held in a certain position
in order to measure wind speed, etc.?
-Will I find using the barometric pressure mode or the
alternative altimeter mode more effective in areas of
limited elevation change? (Most of the areas that I
travel have less than 1400 ft (427 m) of change).
-Will I be able to handle the unit while wearing
gloves as it will be used in mostly cold weather?
-Is the lanyard of sufficient length so that I could
retrieve it easily from a jacket or pack pocket
without unfastening the lanyard?
-Does the battery last 300 hours in very cold
conditions? Many of my trips will be in sub-zero temps
- How will this affect the battery life?
-How long will the battery last with frequent use of
the backlight? (I see this as an important asset to be
able to see the numbers.)
-If I do need to change the battery, can it easily be
replaced with cold fingers?
-Does the clock feature need to be re-set after the
battery is changed?
-Will the unit need to be protected from wet snow and
rain while using it in the field or is it completely
waterproof as suggested?
-How will I know that the pressure sensor needs to be
re-calibrated? Will that be difficult?
-Is there a way to track temperatures over a period of
hours? The website suggests that there is no storage
on that model - does that only mean long term data or
will it track and store for a few hours?
-The user manual says that it will store temperatures
as low as -22F (-30 C) but the batteries and crystal
will not operate below 14 F (-10 C), will I have to
keep the unit inside of my jacket to protect it from
lower temperatures that I will surely encounter? If I
do, how accurate will it be to take it out of hiding
and take a measurement?
-Will moisture or snow clog the impeller?
-Will the wind speed reading be accurate if snow
hinders the impeller?
-Will the impeller last through the test period? The
website says it is replaceable so how often will that
be needed if it is exposed to high winds?
-Will the dewpoint function come in handy for knowing
at what temperature the air will become saturated and
condensation will be heavy? (I see this as important
when selecting the set-up pattern of my tarp. I don't
like having the tarp touch my body or gear when there
is heavy condensation possibilities).
-Will the unit withstand ordinary handling and cartage
or will it have to be protected with a padded case?
-Will the external thermistor that measures
temperatures have to be protected for it to operate
-Will the impeller break easily and have to be
-Will the case hold up to ordinary use?
-Will the plastic used in the construction of the unit
crack when exposed to cold temperatures or if it is
-Is the design of the unit such that I can easily
handle it? Will it require two hands or one hand to
operate it? The finger groove on the back of the unit
allows it to be easily handled with bare hands (I will
report on using it with gloves later). I only needed
one hand to operate it.
-Will the size of the unit be comfortable in a woman's
smaller hand or will it be too big to handle? Very
-Is there any special care that needs to be done to
keep the unit functioning properly?
-What is the ideal temperature to store the unit at
when not in use?
I will gladly address all these issues and any
additional pertinent concerns as I test the Kestrel
3500 Pocket Wind Meter. Thanks to Nielsen-Kellerman
and BackpackGearTest for this great opportunity during
the next four months.
This concludes my Initial Report. My Field Report
should be completed after two months of testing.
Small thumbnail photo courtesy of: Nielsen-Kellerman
**There is a pleasure in the pathless woods** - Lord Byron
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