Kestrel 3500 Pocket Weather Meter
The Kestrel 3500 Pocket Weather Meter is a small, pocket-sized electronic rotating vane type of anemometer (wind meter) with built-in temperature, humidity and barometric pressure sensors. It uses high precision Zytel bearings and a light weight impeller to provide accurate air flow measurements even at low speeds. The impeller assembly is replaceable by the user in the case of damage.
A trend arrow displays whether the pressure is rising, stable or falling, this trend is calculated over a 3-hour period. The pressure is monitored even when the Kestrel 3500 is switched off.
Wind chill and heat index are equivalent temperatures that show the user how their environment really feels. Wind chill is the combination of wind speed and temperature, while heat index is the combined effect of air temperature and relative humidity. The humidity sensor compensates for temperature changes and is designed for stability and accuracy.
The liquid crystal display has large 9mm high digits and is backlit for a clear readout in low light conditions. For users with after dark requirements, the new Kestrel 3500NV, with an olive drab case, has a lower intensity red backlight to preserve night vision.
Power is from an easily replaceable standard lithium coin type cell, which will typically give up to 300 hours of operation. The instrument automatically switches off if no keys are pressed for 45 minutes.
The Kestrel 3500 Pocket Weather Meter is made from high impact injection moulded plastic and corrosion resistant materials with the electronics fully sealed. It will float if accidentally dropped into water. There is a hard cover for protection when not in use and a lanyard is provided for added security.
Kestrel 3500 benefits: What makes a Kestrel Unique?
- Small, robust design
- 3 hour pressure trend
- Data hold function
- Real-time clock
- Large easy to read display with backlight
- Navigation made easy with prompts
- Waterproof and floats
- High precision axle and low-friction Zytel® bearings
- Replaceable impeller
- Fast response temperature sensor
- Long life lithium battery
- Includes protective cover, lanyard and battery
- 5 year warranty
- Choice of measurement units
- Yellow option: standard green backlight
- Olive drab option: low intensity red backlight for preserving night vision
- Agriculture - checking conditions prior to crop spraying or burning
- Aviation - gliders, para-gliders, micro-lights, parachutists and ballooning
- Construction - site safety, working conditions, working at height in cranes or access vehicles
- Education - air flow experiments, environmental studies, outdoor sports
- Heating and ventilation - air flow through fans, checking condition of filters
- Industry - air flow measurements, pollution control
- Science - aerodynamics, environmental science and meteorology
- Fire fighters - checking fire spreading hazard
- Outdoor activities - sailors, walkers, model boats/air craft, kite flyers, archery, shooting, fishing, golf & athletics
or Air Velocity
|m/s||0.1||Larger of 3% of reading, least significant digit or 20 ft/min||0.6 to 60.0 m/s|
0.6 to 40.0 m/s
|1 inch diameter impeller with precision axle and low-friction Zytel® bearings.|
Start-up 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 start-up.
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).
|ft/min||1||18 to 11,811 ft/min|
118 to 7,874 ft/min
|km/h||0.1||2.2 to 216.0 km/h|
2.2 to 144.0 km/h
|mph||0.1||1.3 to 134.2 mph|
1.3 to 89.5 mph
|knots||0.1||1.2 to 116.6 knots|
1.2 to 77.8 knots
|Beaufort||1||0 to 12 B|
|Temperature||°F||0.1||1.8 °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 insulation effect. Calibration drift negligible.|
|°C||0.1||1.0 °C||-45.0 to 125.0|
-29.0 to 70.0
|Relative Humidity||%RH||0.1||3.0 %RH||0.0 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).|
|Pressure||inHg||0.01||typical 0.04 inHg|
max 0.07 inHg
|0.30 to 32.48 inHg||Air 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.|
|hPa (mb)||0.1||typical 1.5 hPa|
max 2.5 hPa
|300.0 to 1100.0 hPa 10.0 to 1100.0 hPa|
|Wind Chill||°F||0.1||1.8 °F||Refer to stated ranges for wind speed and temp.||Perceived temperature resulting from combined effect of wind speed and temperature. Calculated 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.|
|Heat Index||°F||0.1||3.6 °F||Refer 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.)|
|Wet Bulb Temperature (Psychrometric)||°F||0.1||3.6 °F||Refer 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.|
|Dewpoint||°F||0.1||3.6 °F||Refer to stated ranges for temp. and relative humidity.||Temperature to which the air must be cooled at a constant pressure for water vapour to condense into water. Calculated from temperature and relative humidity.|
|Altitude||ft||1||typical 50 ft|
max 98 ft
|-2,300 to 85,000 ft||Height above Mean Sea Level ("MSL"). Temperature compensated pressure (barometric) altimeter requires accurate reference barometric pressure to produce maximum absolute accuracy.|
|m||1||typical 15 m|
max 30 m
|-700 to 25,900 m|
|Max/Avg Wind||One-button clear and restart of Max Wind Gust and Average Wind measurement by powering down and restarting unit.|
|Display & Backlight||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.|
|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.|
|Clock / Calendar||Real-time hours:minutes clock.|
|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.|
|Auto Shutdown||After 45 minutes of no key presses.|
|Certifications||CE certified, RoHS and WEEE compliant. Individually tested to NIST-traceable standards (written certificate of tests available at additional charge).|
|Battery||CR2032, one, included. Average life, 300 hours. Battery life reduced by backlight use in 2000 to 3500 models.|
|Environmental||Waterproof (IP67 and NEMA-6). MIL-STD-810F, Transit Shock, Method 516.5 Procedure IV; unit only; impact may damage replaceable impeller.|
|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).|