Kestrel® 4200 Pocket Air Flow Tracker

Specifications

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Primary Measurement100020002500300035003500
DT		4000420042504300440045004500
HOR		UnitsResolutionAccuracy (+/-)Range:
Max Operational
Specification (if less)		Notes

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Wind Speed
or Air Velocity		•••••••••••••m/s0.1Larger of 3% of reading, least significant digit or 20 ft/min0.6 to 60.0 m/s
0.6 to 40.0 m/s		1 inch 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% @ 5° off-axis; -2% @ 10°; -3% @ 15°. 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).

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ft/min1118 to 11,811 ft/min
118 to 7,874 ft/min

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km/h0.12.2 to 216.0 km/h
2.2 to 144.0 km/h

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mph0.11.3 to 134.2 mph
1.3 to 89.5 mph

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knots0.11.2 to 116.6 knots
1.2 to 77.8 knots

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Beaufort10 to 12 B

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Temperature ••••••••••••°F0.11.8 °F-49.0 to 257.0
-20.0 to 158.0		Air, water or snow temperature. Hermetically-sealed, precision thermistor mounted externally and thermally isolated (US Patent 5,939,645) for rapid response. Airflow of 2.2 mph | 1 m/s or greater provides fastest response and reduction of insolation effect. Calibration drift negligible.

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°C0.11.0 °C-45.0 to 125.0
-29.0 to 70.0

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Relative Humidity ••••••••••%RH0.13.0 %RH0.0 to 100.0%
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 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 +/- 2% over 24 months. RH may be recalibrated at factory or in field using Kestrel Humidity Calibration Kit (NK PN-0802).

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Pressure ••••••••••inHg0.01typical 0.04 inHg
max 0.07 inHg		0.30 to 32.48 inHgAir pressure at the location. Adjustable reference altitude allows display of station pressure or barometric pressure corrected to MSL. Monolithic silicon piezoresistive pressure sensor with second-order temperature correction. Pressure sensor may be recalibrated at factory or in field. Kestrel 2500 and 3500 display continuously updating three-hour barometric pressure trend indicator: rising rapidly, rising, steady, falling, falling rapidly. Kestrel 4000 series displays pressure trend through graphing function.

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hPa (mb)0.1typical 1.5 hPa
max 2.5 hPa		 300.0 to 1100.0 hPa 10.0 to 1100.0 hPa

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PSI0.01typical 0.02 PSI
max 0.04 PSI		0.14 to 15.95 PSI

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Wind Direction
Forward Heading		••°15°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).

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Cardinal16 Points5°0 to 360°

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Air Flow •cfm1Larger of 3% of reading, least significant digit or 20 ft/min0 to 99,999 cfmVolume of air flowing through an opening. Automatically calculated from Air Velocity measurement and user-specified duct shape (circle or rectangle) and dimensions (units: in, ft, cm or m). Maximum duct dimension input: 258.0 in | 21.5 ft | 655.3 cm | 6.55 m.

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m3/hr10 to 99,999 m3/hr

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m3/m10 to 99,999 m3/m

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m3/s0.10.0 to 9,999.9 m3/s

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L/s10 to 99,999 L/s

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Crosswind &
Headwind/Tailwind		••mph110%Refer to stated ranges for wind speed.Effective wind relative to a target or travel direction. Calculated from wind speed, wind direction and target heading. Auto-switching headwind/tailwind indication.

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ft/min110%

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km/h0.110%

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m/s0.110%

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knots0.110%

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Wind Chill ••••••••••••°F0.11.8 °FRefer to stated ranges for wind speed and temp.Perceived temperature resulting from combined effect of wind speed and temperature. Caclulated based on 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.

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°C0.11.0 °C

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Heat Index ••••••••••°F0.13.6 °FRefer to stated ranges for temp. and relative humidity.Perceived temperature resulting from the combined effect of temperature and relative humidity. Calculated based on NWS Heat Index (HI) tables. (Specification temperature limits established by HI tables.)

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°C0.12.0 °C

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Wet Bulb Temperature (Psychrometric)•••••••••°F0.13.6 °FRefer to stated ranges for temp., relative humidity and pressure.Temperature indicated by a wet bulb psychrometer under forced aspiration. Calculated from temperature, relative humidity and pressure.

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°C0.12.0 °C

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Dewpoint ••••••••••°F0.13.6 °FRefer to stated ranges for temp. and relative humidity.Temperature to which the air must be cooled at a constant pressure for water vapor to condense into water. Calculated from temperature and relative humidity.

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°C0.12.0 °C

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Delta T•°F0.15.4 °FRefer to stated ranges for temp., relative humidity and pressure.Difference between dry bulb temperature and wet bulb temperature. When spraying, indicates evaporation rate and droplet lifetime. Safe range for pesticide spraying is 4 to 16 °F / 2 to 9 °C.

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°C0.13.0 °C

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Evaporation Rate•lb/ft2/hr0.01typical 0.02 lb/ft2/hr
typical 0.06 lb/ft2/hr		0.00 to 1.00 lb/ft2/hrThe rate at which moisture is lost from the surface of curing concrete. Calculated from wind speed, temperature, relative humidity and concrete temperature. Requires user measurement and entry of concrete temperature obtained with an accurate IR or probe thermometer (°F or °C, not included). Readings should be taken 20 inches above pour surface with the thermistor shaded, and averaged for 6-10 seconds using built-in averaging function.

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kg/m2/hr0.01typical 0.1 kg/m2/hr
max 0.1 kg/m2/hr		0.00 to 5.00 kg/m2/hr

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Altitude ••••••••••ft1typical 50 ft
max 98 ft		-2,300 to 85,000 ftHeight above Mean Sea Level ("MSL"). Temperature compensated pressure (barometric) altimeter requires accurate reference barometric pressure to produce maximum absolute accuracy.

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m1typical 15 m
max 30 m		-700 to 25,900 m

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Density Altitude •••••••ft1246Refer to stated ranges for temp., relative humidity and pressure.Air density converted to equivalent sea level elevation at the International Standard Atmosphere. Calculated from temperature, pressure and relative humidity.

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m175

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Max/Avg Wind••••••One-button clear and restart of Max Wind Gust and Average Wind measurement by powering down and restarting unit.

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•••••••Max and average wind calculation may be started and stopped independently of data logging of other values, along with all other wind-related functions: air velocity, crosswind, headwind/tailwind, wind chill, WBGT, TWL, evaporation rate.

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Data Storage & Graphical Display, Min/Max/Avg History•
4000		•
3600		•
3600		•
3200		•
2400		•
2900		•
2500		Minimum, maximum, average and logged history stored and displayed for every measured value. Large capacity data logger with graphical display. Manual and auto data storage. Min/Max/Avg history may be reset independently. Auto-store interval settable from 2 seconds to 12 hours, overwrite on or off. Logs even when display off except for 2 and 5 second intervals (code version 4.18 and later). Data set capacity by model shown.

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Data Upload•••••••Requires optional PC interface (USB or RS-232) or Bluetooth enabled model and provided software.

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Available Bluetooth®
Data Connect		•••••••Adjustable power consumption and radio range from up to 30 ft | 9 meters. Individual unit ID and 4-digit PIN code preprogrammed for easy identification and data security when pairing and transmitting. Employs Bluetooth Serial Port Protocol for data transmission.

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Display & Backlight•••Reflective 3 1/2 digit LCD. Digit height 0.36 in / 9 mm. Aviation green electroluminescent backlight (except in Kestrel 1000). Manual activation with auto-off.

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•••Reflective 5 digit LCD. Digit height 0.36 in / 9 mm. Choice of aviation green or visible red (NV models only) electroluminescent backlight. Manual activation with auto-off.

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•••••••Multifunction, multi-digit monochrome dot-matrix display. Choice of aviation green or visible red (NV models only) electroluminescent backlight. Automatic or manual activation.

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Response Time & Display Update•••••••••••••All measurements except those based on relative humidity respond accurately within 1 second. Relative humidity and all measurements which include RH in their calculation may require as long as 1 minute to fully equilibrate to a large change in the measurement environment. Display updates every 1 second.

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Clock / Calendar•••Real-time hours:minutes clock.

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•••••••Real-time hours:minutes:seconds clock, calendar, automatic leap-year adjustment.

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Operational & Storage Temperature Range•••••••••••••The operational temperature range of the liquid crystal display and batteries is 14° F to 131° F / -10 °C to 55 °C. Measurements beyond the operational range can be taken by briefly exposing unit to extreme conditions such that the display and batteries remain within the operational range. Storage range -22 °F to 140 °F / -30 °C to 60 °C.

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Auto Shutdown••••••After 45 minutes of no key presses.

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•••••••User-selectable -- 15 or 60 minutes with no key presses or disabled.

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Languages•••••••English, French, German, Italian, Spanish.

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Certifications•••••••••••••CE certified, RoHS and WEEE compliant. Individually tested to NIST-traceable standards (written certificate of tests available at additional charge).

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Battery••••••CR2032, one, included. Average life, 300 hours. Battery life reduced by backlight use in 2000 to 3500 models.

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•••••••AAA Alkaline, two, included. Average life, 400 hours of use, reduced by backlight or Bluetooth radio transmission use.

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Environmental•••••••••••••Waterproof (IP67 and NEMA-6). MIL-STD-810F, Transit Shock, Method 516.5 Procedure IV; unit only; impact may damage replaceable impeller.

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Size & Weight••••••4.8 x 1.9 x 1.1 in / 12.2 x 4.8 x 2.8 cm, 3.6 oz / 102 g (including slip-on cover).

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••••••5.0 x 1.8 x 1.1 in / 12.7 x 4.5 x 2.8 cm, 3.6 oz / 102 g.

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•6.5 x 2.3 x 1.1 in / 16.5 x 5.9 x 2.8 cm, 4.4 oz / 125 g.

Full Kestrel Specifications PDF
English (40.3 KB) | French (25.8 KB) | German (23.8 KB) | Italian (24.7 KB) | Portuguese (25.1 KB) | Spanish (24.9 KB)


RoHS Certificate of Compliance
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