KESTREL 1000-3500 SERIES  SENSORS

SENSOR

ACCURACY (+/-)

RESOLUTION

SPECIFICATION RANGE

NOTES

Wind Speed |Air Speed

Larger of 3% of reading, least significant digit or 20 ft/min

0.1 m/s 1 ft/min

0.1 km/h

0.1 mph

0.1 knots 1 B

0.6 to 40.0 m/s 118 to 7,874 ft/min

2.2 to 144.0 km/h

1.3 to 89.5 mph

1.2 to 77.8 knots 0 to 12 B

1 inch|25 mm diameter impeller with precision axle and low-friction Zytel® bearings. Startup speed stated as lower limit, readings may be taken down to

0.4 m/s |79 ft min|1.5 km/h |.9 mph |.8 kt after impeller startup. Off-axis accuracy

-1% @ 5º off axis; -2% @ 10º; -3% @ 15º. Calibration drift < 1% after 100 hours use at 16 MPH |7 m/s. Replacement impeller (NK PN-0801) field installs without tools (US Patent 5,783,753). Wind speed calibration and testing should be done with triangle on impeller located at the top front face of the Kestrel. Measuring wind speeds above 60 m/s / 134.2 mph can damage the impeller.

Ambient Temperature

0.9 °F

0.5 °C

0.1 °F

0.1 °C

-20.0 to 158.0 °F

-29.0 to 70.0 °C

Airflow of 2.2 mph|1 m/s or greater provides fastest response and reduction of insolation effect. For greatest accuracy, avoid direct sunlight on the temperature sensor and prolonged sunlight exposure to the unit in low airflow conditions.

Calibration drift is negligible for the life of the product. For further details, see Display & Battery Operational Temperature Limits.

Relative Humidity

3%RH

0.1 %RH

5 to 95% 25°C non-condensing

To achieve stated accuracy, unit must be permitted to equilibrate to external

temperature when exposed to large, rapid temperature changes and be kept out of direct sunlight. Calibration drift is typically less than ±0.25% per year.

Pressure

1.5 hPa|mbar

0.044 inHg

0.022 PSI

0.1 hPa|mbar

0.01 inHg

0.01 PSI

25°C/77°F

750-1100 hPa|mbar

22.15-32.48 inHg

10.88-15.95 PSI

Monolithic silicon piezo-resistive pressure sensor with second-order temperature correction. Between 1100–1600 mbar, unit will operate with reduced accuracy. Sensor may not operate above 1600 mbar and can be damaged above 6,000

mbar or below 10 mbar. Calibration drift is negligible for the life of the product.

CALCULATED MEASUREMENTS

MEASUREMENT

ACCURACY (+/-)

RESOLUTION

SENSORS EMPLOYED

Altitude

typical: 23.6 ft/7.2 m from 750 to 1100 mBar max: 48.2 ft/14.7 m

from 300 to 750 mBar

1 ft

1 m

Pressure, User Input (Reference Pressure)

Barometric Pressure

0.07 inHg

2.4 hPa|mbar

0.03 PSI

0.01 inHg

0.1 hPa|mbar

0.01 PSI

Pressure, User Input (Reference Altitude)

Delta T

3.2 °F

1.8 °C

0.1 °F

0.1 °C

Temperature, Relative Humidity, Pressure

Dew Point

3.4 °F

1.9 °C

15-95% RH.

Refer to Range

for Temperature Sensor

0.1 °F

0.1 °C

Temperature, Relative Humidity

Heat Index

7.1°F

4.0°C

0.1 °F

0.1 °C

Temperature, Relative Humidity

Wet Bulb Temperature - Psychrometric

3.2 °F

1.8 °C

0.1 °F

0.1 °C

Temperature, Relative Humidity, Pressure

Wind Chill

1.6 °F

0.9 °C

0.1 °F

0.1 °C

Wind Speed, Temperature

ADDITIONAL PRODUCT INFO

KESTREL 5 SERIES SENSORS

ADDITIONAL PRODUCT INFO

KESTREL DROP SENSORS

ACCURACY (+/-)

RESOLUTION

SPECIFICATION RANGE

NOTES

Ambient Temperature

0.9 °F

0.5 °C

0.1 °F

0.1 °C

14 to 131°F

-10 to 55 °C

Airflow of 2.2 mph|1 m/s or greater provides fastest response and reduction of insolation effect. For greatest accuracy, avoid direct sunlight on the temperature sensor and prolonged sunlight exposure to the unit in low airflow conditions.

Relative Humidity

2%RH

0.1 %RH

10 to 90% 25°C non- condensing

To achieve stated accuracy, unit must be permitted to equilibrate to external temperature when exposed to large, rapid temperature changes and be kept out of

Pressure

1.5 hPa|mbar

0.044 inHg

0.022 PSI

0.1 hPa|mbar

0.01 inHg

0.01 PSI

25°C/77°F

700-1100 hPa|mbar

20.67-32.48 inHg

10.15-15.95 PSI

Monolithic silicon piezo-resistive pressure sensor with second-order temperature correction. Between 1100–1600 mbar, unit will operate with reduced accuracy. Sensor may not operate above 1600 mbar and can be damaged above 6,000 mbar

CALCULATED MEASUREMENTS

MEASUREMENT

ACCURACY (+/-)

RESOLUTION

SENSORS EMPLOYED

Density Altitude

226 ft

69 m

1 ft

1 m

Temperature, Relative Humidity,

Pressure

Dew Point

3.4 °F

1.9 °C

15-95% RH. Refer to Range

for Temperature Sensor

0.1 °F

0.1 °C

Temperature, Relative Humidity

Heat Index

7.1°F

4.0°C

0.1 °F

0.1 °C

Temperature, Relative Humidity

THI (NRC)

1.5 °F

0.8 °C

0.1 °F

0.1 °C

Temperature, Relative Humidity

THI (Yousef)

2.3 °F

1.3 °C

0.1 °F

0.1 °C

Temperature, Relative Humidity

Wet Bulb Temperature - Psychrometric

3.2 °F

1.8 °C

0.1 °F

0.1 °C

Temperature, Relative Humidity

Pressure

ADDITIONAL PRODUCT INFO

Response Time & Display Update

Display updates every 1 second. After exposure to large environmental changes, all sensors require an equilibration period to reach stated accuracy. Measurements employing RH may require longer periods particularly after prolonged exposure to very high or very low humidity. WBGT requires about 8 minutes to reach 95% accuracy and about 15