Kestrel 3000 Pocket Weather Instruction Manual

3000

Pocket Weather ® Meter

with Backlight

Revised 05/07

INSTRUCTION MANUAL

Thank you for purchasing the Kestrel 3000 Pocket
Weather Meter. This instrument will measure the following
environmental conditions:

• wind speed • wind chill

• maximum wind gust • relative humidity

• average wind speed • heat stress

• temperature (air, water, snow) • dewpoint

This instrument also features a data hold function, a backlight,
and an automatic power-down function. Every unit is
fully tested at our factory for measurement accuracy and
waterproof integrity.

OPERATION

1. Slide off cover.

2.

Turn on. Press the center button ( or ) to turn on the unit.

3. Select operating mode. Press the right arrow (

) to scroll through the measurements
listed below. Press the left arrow ( or ) to scroll through the measurements in reverse
order. The instantaneous measurements will be displayed. (See Understanding the
Measurements section for more information.)

mph

mph

MAX

mph

AVG

Current

Wind Speed

Maximum 3­Second Gust

Since Power On

Average Wind

Speed Since

Power On

MAX

AVG

or

2

4. Select the units of measure. Press

while holding or to scroll through the units

of measure.

5.

Hold mode. Press or while holding or to hold the measured value on the display. The

word “HOLD” will blink to indicate the Hold Mode. Press or while holding or to exit
the Hold Mode. This mode can be useful for taking measurements when unable to view
the display, as within a duct. The Max and Avg Wind Speed Modes will continue to work
as usual.

3

6. Turn on the backlight. Press or to activate the backlight for 10 seconds. If or or
are pressed while the backlight is illuminated, the backlight will remain illuminated for

another 10 seconds. Press or while the backlight is illuminated to manually turn off the
backlight.

7.

Turn off. Hold or for 2 seconds to manually turn off the unit. The unit will automatically
turn off if no buttons have been pressed for 45 minutes.

UNDERSTANDING THE MEASUREMENTS

Wind Speed - average over the previous three seconds. The measurement will be accurate

for air flow through the front or rear of the unit.

Maximum Wind Gust - maximum 3 - second wind speed since the unit was turned on.

Average Wind Speed - average wind speed since the unit was turned on.

Temperature - instantaneous temperature of the thermistor, which is located at the end

of the long coiled leads in the open cavity below the impeller. The exposed thermistor will
respond quickly to changes in temperature when air flows past it. For fastest response, either
hold the unit into the wind or wave the unit side to side for 15 seconds. Readings should be
taken in the shade. Water and snow temperatures can be taken by hold the unit in the water
or snow.

4

Wind Chill - combination of wind speed and temperature, as defined by the US National
Weather Service. Wind chill is the effective temperature on a human or animal at low
temperatures due to wind speed. Wind chill readings will be the same as the temperature
readings above 45ºF or below 3 mph.

Relative Humidity - amount of moisture in the air compared to the amount of moisture the
air can hold for the given temperature, represented as a percent. Because relative humidity is
also a function of the temperature, the response time will be dependent on the temperature
response time (see temperature section above). Readings should be taken in the shade.

Heat Stress – combination of temperature and humidity, as defined by the US National
Weather Service. Heat stress is the effective temperature on a human or animal at high
temperatures due to humidity. Heat stress readings will be the same as the temperature
readings below 70ºF.

Dewpoint – calculated based on temperature and humidity measurements, as a measure of
moisture content in the air. If the dewpoint is very close to the temperature, the air is humid.
If the temperature and dewpoint are the same, dew will form. If this happens below freezing,
frost will form.

5

MAINTENANCE & TROUBLESHOOTING

Environmental

Every Kestrel Meter is fully waterproof and floats, and has passed mil-spec drop testing.

Storing Your Kestrel

Avoid storing your Kestrel where it will be exposed to temperatures below -30°C [-22°F] or
above 60° C [176° F] for extended periods of time. Doing so may cause permanent damage.
(Note that the inside of a car parked in the hot sun can reach very high temperatures.)

Use of the Lanyard and Cover

The cover can be captured on the lanyard to avoid loss. First, remove the cord poplock. Then
feed the lanyard end through the large opening in the over and out the slot. Replace the
poplock on the lanyard.

Replacing the Battery

When your display becomes dim or disappears, replace the
battery. Use a large coin to open the battery compartment.
Use only new CR2032 coin cell batteries (available where
watch batteries are sold). Wipe the battery clean of any
fingerprints and insert the positive (+) pole up, angling the
battery downward and pressing it firmly into place. When
replacing the battery door, be sure to keep the black rubber
o-ring seated in the groove on the case back.

Replacing the Battery

6

Why does the Impeller Appear Imbalanced?

It is NORMAL for the impeller to oscillate as it comes to a stop. It is NOT imbalanced. Rather,
it contains a very small magnet that responds to the earth’s magnetic fields. This does not
affect the accuracy of the wind speed readings because the magnetic field applies both a
braking and an accelerating force which cancel each other. The impeller has been calibrated
to provide wind speed readings accurate to within at least ± 3%.

High Speed Use

After several hours of sustained operation over 25 M/S (~49
KT, 90 KM/H, 56 MPH or 4,923 FPM), the Kestrel will lose some
accuracy due to wear of the sapphire bearings in the impeller.

Replacing the Impeller

You may recalibrate the wind speed readings by replacing
the impeller. Press FIRMLY on the sides of the black impeller
housing with your thumbs to remove the entire assembly.
When inserting the new impeller, be sure the arrow is facing
the display side of the unit, and is aligned with the top of the
meter. Press on the sides of the housing rather than the center.

Taking Accurate Humidity, Heat Stress and Dewpoint Measurements

The patented system for measuring relative humidity allows for extremely fast and accurate
readings. The sensor is located in the large hole on the rear of the unit. Even extreme and
abrupt changes in the surrounding humidity will be measured within several minutes. To test
this, place your hand around the rear of the unit. Within several seconds, the humidity will

Replacing the Impeller

7

increase dramatically. After removing your hand, the humidity will quickly begin to decrease.
Next, place your hand near the rear of the unit and wave the unit back and forth. The
humidity will not change because the air flow is diluting the humidity from your hand.

This example shows the importance of keeping air flow past the sensor while taking a
measurement. If there is no natural air flow past the sensor, wave the unit back and forth.
It is also reasonable to lay the unit down on a solid surface for several minutes to allow the
sensor to adjust.

Sensors & Calibration

Kestrel Pocket Weather Meters use precision sensors to measure the environment. These
sensors have all been factory calibrated to NIST-traceable standards, and are accurate within
the stated specifications at the time of manufacture.

The wind is measured with the patented user-replaceable impeller. It is mounted on a
sapphire bearing that begins to measure readings in the slightest of breezes.

The patented external temperature sensor is mounted on long, coiled leads that help
to further isolate the bulb from the case. This ensures that the Kestrel is reading the air
temperature and not the case temperature, may be warmer if the unit was in your pocket or
warmed by your hand.

The patented relative humidity sensor is designed to adjust quickly to abrupt changes in
humidity, and maintains this accuracy and speed in extremely low humidity conditions.
The RH sensor is located on the back of the unit and is protected by a membrane. DO NOT
puncture this membrane. It will damage the sensor and require replacement.

8