|
Measurement
Response Time |
Units |
Operational
Range |
Resolution |
Accuracy
(+/-) |
Specification
Range |
Wind
Speed
1 second |
m/s |
0.4 to 60.0
m/s |
0.1 |
Larger
of 3% of reading or least significant
digit |
0.4
to 40.0 m/s |
ft/min |
59
to 11,948 ft/min |
1 |
59 to 7877
ft/min |
km/h |
1.0
to 218.0 km/h |
0.1 |
1.0 to 144.0
km/h |
mph |
0.8
to 135.0 mph |
1 |
0.8
to 89.0 mph |
knots |
0.6
to 118.3 kt |
0.1 |
0.6 to 78.0
kt |
Beaufort |
0
to 12 B |
0.1 |
0 to 12 B |
1
inch diameter impeller with precision axle
and sapphire bearings. Off-axis accuracy
-1% @ 5º off-axis; -2% @ 10º; -3%
@ 15º. Calibration drift < 1%
after 100 hours use at 16 MPH / 7 m/s.
Sustained operation above 60 MPH / 27 m/s
will wear impeller rapidly and may cause destruction
of impeller. Replacement impeller (NK
PN-0801) may be field-installed without tools
(US Patent 5,783,753). |
Wind
Direction / Forward Heading
1 second |
° |
360° |
1 |
5° |
0 to 360° |
Cardinal
Points |
360° |
16 Points |
5° |
0 to 360° |
2-axis
solid-state magnetoresistive sensor mounted
perpendicular to unit plane to permit operation
while measuring wind speed. Declination/variation
adjustable for True North readout. Accuracy
of measurements dependent upon unit's vertical
position. Self-calibration routine eliminates
magnetic error from batteries or unit and
must be run after every full power-down (battery
removal or change). |
Temperature
1 second |
°F |
-49.0
to 257.0 °F |
0.1 |
1.8
°F |
-20.0
to 158.0 °F |
°C |
-45.0 to
125.0 °C |
0.1 |
1.0
°C |
-29.0
to 70.0 °C |
Measures
air, water and snow temperature. Thermally
isolated, hermetically sealed, precision thermistor
mounted externally (US Patent 5,939,645).
Calibration drift negligible. |
Relative
Humidity
1 minute |
%RH |
0.0
to 100.0 % |
0.1 |
3.0
%RH |
5.0
to 95.0 % non-condensing |
Polymer
capacitive humidity sensor mounted in thin-walled
chamber external to case for rapid, accurate
response (US Patent 6,257,074). (To
achieve stated relative humidity accuracy,
unit must be permitted to equilibrate to external
temperature when exposed to large, rapid temperature
changes and must be kept out of direct sunlight.)
Calibration drift +/- 2% over 24 months. Relative
humidity may be recalibrated at factory or
in field using Kestrel Humidity Calibration
Kit (NK PN-0802). |
Pressure
1 second
(mb & PSI 4000 model only) |
inHg |
8.86
to 32.48 inHg |
0.01 |
0.05
inHg |
At
77.0 °F, <19,700 ft |
hPa
/ mb |
300.0 to
1100.0 hPa / mb |
0.1 |
1.5
hPa / mb |
At
25.0 °C, <6,000 m |
PSI |
4.4 to 16.0
PSI |
0.1 |
0.1
PSI |
At
77.0 °F, <19,700 ft |
Monolithic
silicon piezoresistive pressure sensor with
second-order temperature correction.
Maximum error beyond specified temperature,
+/- 0.09 inHg / 3.0 hPa. Calibration
drift typically -0.03 inHg / -1.0 hPa per
year. Pressure sensor may be recalibrated
at factory or in field. |
Altitude
1 second |
ft |
-6000
to 30000 ft |
1 |
50
ft |
At
77.0 °F, <19,700 ft. Max error +/-
98 ft |
m |
-2000
to 9000 m |
1 |
15
m |
At
25.0 °C, <6,000 m. Max error
+/- 30 m |
Temperature
compensated pressure (barometric) altimeter. |
Crosswind
Headwind, Tailwind
1 second |
mph |
0.8 to 135.0
mph |
1 |
5% |
8.5 to 89.0
mph |
ft/min |
59 to 11,880
ft/min |
1 |
5% |
750 to 7832
ft/min |
km/h |
1.0 to 217.3
km/h |
0.1 |
5% |
13.7 to 143.2
km/h |
m/s |
0.4 to 60.0
m/s |
0.1 |
5% |
3.8 to 40.0
m/s |
knots |
0.6 to 117.3
kt |
0.1 |
5% |
7.4 to 77.0
kt |
Calculated
from the primary measurements of wind speed,
wind direction and target heading. Auto-switching
headwind/tailwind indication. Ranges
expressed refer to primarywind speed. |
Wind
Chill
1 second |
°F |
0.7
to 135.0 MPH, -49.0 to 257.0 °F |
0.1 |
1.8 °F |
1.8
to 89.0 mph, -50.0 to 50.0 °F |
°C |
0.4
to 60.0 m/s, -45.0 to 125.0 °C |
0.1 |
1.0
°C |
0.4
to 40 m/s, -45.6 to 10.0 °C |
Calculated
from the primary measurements of wind speed
and temperature. Utilizes the NWS Wind
Chill Temperature (WCT) Index, revised 2001,
with wind speed adjusted by a factor of 1.5
to yield equivalent results to wind speed
measured at 10 m above ground. (Specification
temperature limits established by WCT Tables.) |
Heat
Index
1 minute |
°F |
0.0
to 100.0 %RH, -49.0 to 257.0 °F |
0.1 |
3.6 °F |
70.0
to 130.0 °F, 0 to 100% RH |
°C |
0.0
to 100.0 %RH, -45.0 to 125.0 °C |
0.1 |
2.0
°C |
21.1
to 54.4 °C, 0 to 100 %RH |
Calculated
from the primary measurements of temperature
and relative humidity. Utilizes the
NWS Heat Index (HI) tables. (Specification
temperature limits established by HI tables.) |
Dewpoint
1 minute |
°F |
0.0
to 100.0 %RH, -49.0 to 257.0 °F |
0.1 |
3.6 °F |
-20.0
to 158.0 °F, 20.0 to 95.0% RH |
°C |
0.0
to 100.0 %RH, -45.0 to 125.0 °C |
0.1 |
2.0
°C |
-29.0
to 70.0 °C, 20.0 to 95.0 %RH |
Calculated
from the primary measurements of temperature
and relative humidity. Temperature to which
the air would need to be cooled at a constant
pressure to become saturated. |
Wet
Bulb Temperature
1 minute |
°F |
-49.0
to 257.0 °F, 0.0 to 100.0 %RH, 8.86
to 32.48 inHg |
0.1 |
3.6 °F |
32.0
to 100.0 °F, 5.0 to 95.0% RH, 8.86 to
32.48 inHg, <19700 ft |
°C |
-45.0
to 125.0 °C, 0.0 to 100.0 %RH, 300.0
to 1100.0 hPa |
0.1 |
2.0
°C |
0.0
to 37.8 °C, 5.0 to 95.0 %RH, -2000.0
to 9000.0 hPa, <6000 m |
Calculated
from the primary measurements of temperature,
relative humidity and pressure. Temperature
indicated by a wet bulb psychrometer. |
Density
Altitude
1 second |
ft |
-49.0
to 257.0 °F, 0.0 to 100.0 % RH, 8.86
to 32.48 inHg |
1 |
246 |
32.0
to 100.0 °F, 5.0 to 95.0 %RH, 8.86
to 32.48 inHg, <19700 ft |
m |
-45.0
to 125.0 °C, 0.0 to 100.0 %RH, 300.0
to 1100.0 hPa |
1 |
75 |
0.0
- 37.8 °C, 5.0 to 95.0 %RH, -2000
to 9000 hPa, <6000 m |
Calculated
from the primary measurements of temperature,
relative humidity and pressure. Air
density converted to equivalent sea level
elevation at the International Standard Atmosphere. |
Max/Avg
Wind Speed (Air Velocity),
Crosswind, Headwind/Tailwind |
One-button
clear and restart of Max Wind Gust and Average
Wind measurement. |
Data
Storage / Display |
Minimum,
maximum, average and logged history stored
and displayed for every measured value. 1400-point
data logger with graphical display. Auto data
storage; interval settable from 2 seconds
to 12 hours. Manual data capture. |
Data
Upload |
Requires
optional PC interface (NK PN-0830) and provided
software. RS-232 connection with USB adapter
available. |
Display |
Multifunction,
multi-digit programmable dot-matrix display. |
Display
Update |
1
second. |
Display
Backlight |
Choice
of aviation green or visible red electroluminescent
backlight. Automatic or manual activation. |
Clock
/ Calendar |
Real-time
hours:minutes:seconds clock, calendar, automatic
leap-year adjustment. |
Operational
Temperature Range
(LCD and Batteries) |
The
operational temperature range of the liquid
crystal display and batteries is 14° F
to 131° F / -10 °C to 55 °C. Beyond
the limits of the operational temperature
range, the unit must be maintained within
range and exposed for minimum time necessary
to take reading. |
Storage
Temperature |
-22
°F to 140 °F / -30 °C to 60 °C. |
Auto
Shutdown |
User-selectable:
15 or 60 minutes with no key presses or disabled. |
Languages |
English,
French, German, Italian, Spanish. |
Certifications |
CE
certified. Individually tested to NIST-traceable
standards (written certificate of tests available
at additional charge). |
Batteries |
AAA
Alkaline, two, included. Average life, 400
hours of use, +/-depending on backlight use. |
Environmental |
Waterproof
(IP67 standard). Drop-tested (MIL.STD.810F;
unit only. Substantial impact may damage replaceable
impeller.). |
Dimensions |
Unit
5.0 x 1.8 x 1.1 in / 12.7 x 4.5 x 2.8 cm. |
Weight |
Unit
3.6 oz / 102 g. |
Full
Kestrel Specifications PDF: English
(40.3 KB) |
Kestrel Meters
are designed and manufactured at NK¡¯s facility
in Boothwyn, Pennsylvania, and are individually
calibrated at the time of manufacture. Every
Kestrel Meter comes with a Certificate of
Conformity to document the unit¡¯s accuracy—all
Kestrel measurements are traceable to the
National Institute of Standards and Technology,
ensuring the highest level of reliability.
Additional NIST Calibration and Certification
services are available. |