Richard Paul Russell Ltd
Home > Products > Kestrel Hand-held Weather Meters > Kestrel 4250 > Specification
Home > Products > Kestrel Hand-held Weather Meters > Kestrel 4250 > Specification
| Physical | Dimensions | 126mm x 45mm x 29mm | |
| Weight | 102g | ||
| Lanyards | 0.2m and 0.5m (for wrist and neck) | ||
| Case colour | Safety orange | ||
| Display | Display type | Dot matrix LCD with electro-luminescent backlighting | |
| Display update | 1 second | ||
| Data logging | Programmable 2 second to 12 hour
intervals, 2000 data points with graphical display. Manual data capture. Data upload with optional PC interface. Bluetooth models only: Integrated Bluetooth wireless data transfer with adjustable range from 5 to 30 feet. |
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| Functions | Wind speed (current, maximum and average) | ||
| Temperature | |||
| Relative Humidity | |||
| Moisture content / humidity ratio / water grains | |||
| Calculated Dew Point | |||
| Station pressure | |||
| Barometric pressure | |||
| Air density | |||
| Relative air density | |||
| Density altitude | |||
| Altitude | |||
| Wind chill | |||
| Heat index | |||
| Wet bulb temperature | |||
| Speed units | kt, m/s, km/h, mph, ft/min, Beaufort Force (B) | ||
| Temperature units | ºC, ºF | ||
| Pressure units | mbar, inHg, hPa, psi | ||
| Density altitude units | m, ft | ||
| Air density units | kg/m3, lb/ft3 | ||
| Relative air density units | % | ||
| Moisture content / humidity ratio units | g/kg, gpp | ||
| Altitude units | m, ft | ||
| Date and time display | dd/mm/yy, mm/dd/yy, 12 hour, 24 hour | ||
| Performance | Speed (1 sec response) |
Operational range | 0.4m/s to 60m/s (0.8 to 135.0mph) |
| Specification range | 0.4m/s to 40m/s (0.8 to 89.0mph) | ||
| On axis accuracy | ± 3% of reading or ± 0.1 m/s. (Some loss of accuracy from bearing wear may occur with sustained operation at or near maximum speed) | ||
| Off-axis response | -1% @ 5°, -2% @ 10°, -3% at 15° | ||
| Calibration drift | <2% after 100hrs operation at 7m/s |
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| Resolution | 0.1 kt, m/s, km/h, mph. 1 FPM below 1999 FPM, 10 FPM above 2000 FPM. 1 Beaufort (0 to 12) | ||
| Temperature (1 sec response) |
Operational range | -45.0ºC to +125.0ºC | |
| Specification range | -29.0ºC to +70.0ºC | ||
| Accuracy | ±1ºC | ||
| Resolution | 0.1º | ||
| Wind chill accuracy | ±1.0ºC (from wind speed and temperature) | ||
| Relative Humidity (1 min response) |
Operational range | 0% to 100% | |
| Specification range | 5% to 95% non-condensing | ||
| Resolution | 0.1% | ||
| Accuracy | ±3% (when unit allowed to equilibrate to external temperature) | ||
| Calibration drift | ±2% over 24 months (correctable) | ||
| Heat index accuracy | ±2ºC (between 21.1ºC and 54.4ºC) | ||
| Dew point accuracy | ±2ºC (above 20% relative humidity) | ||
| Pressure (1 sec response) |
Operational range | 10 to 1100 mbar at 25ºC | |
| Specification range | 750 to 1100 mbar at 25ºC | ||
| Resolution | 0.1 mbar | ||
| Accuracy | ±3 mbar (from -10ºC to 60ºC) | ||
| Calibration drift | Typically ±1 mbar per year (correctable) | ||
| Wet bulb temperature accuracy | ±2ºC (between 0ºC and 37.8ºC) | ||
| Density altitude accuracy | ±75m (between 0ºC and 37.8ºC) | ||
| Air density accuracy | ±2% (between 0ºC and 70ºC) | ||
| Moisture content accuracy | 10% (Typical between -29ºC and 54ºC) | ||
| Altitude (1 sec response) |
Operational range | -2000m to +9000m (-6000 ft to +30,000 ft) | |
| Specification range | -2000m to +6000m at 25ºC | ||
| Accuracy | ±15m (max error out of spec range: ±30m) | ||
| Resolution | 1m or 1ft | ||
| Sensors | Impeller | Diameter 25mm High precision axle and jewel (sapphire) bearings User replaceable impeller assembly |
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| Temperature | Hermetically sealed precision thermistor | ||
| Relative Humidity | Polymer capacitive sensor, mounted externally in thin-walled chamber | ||
| Pressure | Monolithic piezo-resistive silicon based sensor with second order temperature correction | ||
| Environmental | Sealing | Electronics enclosure IP67 [Water resistant] | |
| Shock | Drop tested (MIL.STD.810F - unit only) | ||
| Temperature | Operating range: -10ºC to +55ºC (operation
over a wider range is possible with reduced display readability) Storage range: -30ºC to +60ºC |
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| EMC | CE marked | ||
| Miscellaneous | Battery | 2 AAA alkaline, user replaceable | |
| Battery Life | Average expected life: 400 hours of active screen, monitoring and logging use, reduced by backlight and Bluetooth use. | ||
| Auto switch off | Selectable to remain switched on, switch off 15 minutes or 60 minutes after last key press | ||
| Wind chill equivalent temperature calculation | Utilises the (US) NWS Wind Chill Temperature (WCT) Index, revised 2001, with wind speed adjusted by a factor of 1.5 to yield equivalent results for wind speed measured at 10m above ground | ||
| Heat Index calculation | Steadman, from temperature and relative humidity | ||
| Certification | Wind speed, temperature, humidity and
pressure measurements are tested during
manufacture. A certificate of conformity (C of C) is included with each Kestrel. Calibration certificates are available for an additional fee. |
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| Guarantee | 5 years | ||
| The manufactures reserve the right to amend the specification and therefore the information in this document may be subject to change | |||
The Bluetooth® word mark and logos are registered trademarks owned by Bluetooth SIG, Inc. and any use of such marks by Richard Paul Russell Ltd is under license. Kestrel, Kestrel Tracker, Pocket Wind, Pocket Weather and the Kestrel logos are trademarks owned by Neilsen Kellerman. Other trademarks and trade names are those of their respective owners.
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