Industrial Quality and Reliability!
We think their that good we give a 5 Year Warranty*
Barometric pressure - Pressure trend
Altitude - Relative humidity
Heat stress index - Dewpoint
Wet bulb temperature - Wind chill
Air , water , and snow temperature
Current wind speed - Average wind speed
Maximum wind gust
Watch the Drop Test and see how strong they The Kestrel range are!
UNDERSTANDING THE MEASUREMENTS:
Wind Speed - average over the previous three seconds. The measurement will be accurate for air !ow through the front or rear of the unit.
Maximum Wind Gust - maximum 3 - second wind speed since the unit was turned on.
Average Wind Speed - average wind speed since the unit was turned on.
Temperature - instantaneous temperature of the thermistor, which is located at the end of the long coiled leads in the open cavity below the impeller. The exposed thermistor will respond quickly to changes in temperature when air !ows past it. For fastest response, either hold the unit into the wind or wave the unit side to side for 15 seconds. Readings should be taken in the shade. Water and snow temperatures can be taken by hold the unit in the water or snow.
Wind Chill - combination of wind speed and temperature, as de#ned by the US National Weather Service. Wind chill is the e"ective temperature on a human or animal at low temperatures due to wind speed. Wind chill readings will be the same as the temperature readings above 45ºF or below 3 mph.
Relative Humidity - amount of moisture in the air compared to the amount of moisture the air can hold for the given temperature, represented as a percent. Because relative humidity is also a function of the temperature, the response time will be dependent on the temperature response time (see temperature section above). Readings should be taken in the shade.
Heat Stress – combination of temperature and humidity, as de#ned by the US National Weather Service. Heat stress is the e"ective temperature on a human or animal at high temperatures due to humidity. Heat stress readings will be the same as the temperature readings below 70ºF.
Dewpoint – calculated based on temperature and humidity measurements, as a measure of moisture content in the air. If the dewpoint is very close to the temperature, the air is humid. If the temperature and dewpoint are the same, dew will form. If this happens below freezing, frost will form.
Wet Bulb Temperature - calculated based on temperature and humidity measurements, as a measure of evaporation rate. If the wet bulb temperature is very close to the air temperature, the air is humid. Wet bulb temperature is typically measured by swinging a mercury thermometer with a wet sock on its end for several minutes.
Altitude and Barometric Pressure - the Kestrel 3500 will measure station pressure in orderto calculate barometric pressure and altitude. Changes in either air pressure or altitude will affect these readings, so it’s important to make adjustments as necessary.
|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).|
|°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.|
|%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).|
(mb & PSI 4000 model only)
|inHg||0.3 to 32.5 inHg||0.01||0.05 inHg||At 77.0 °F, 22.1 to 32.5 inHg|
|hPa / mb||10.0 to 1100.0 hPa / mb||0.1||1.5 hPa / mb||At 25.0 °C, 750 to 1100 hPa / mb|
|PSI||0.15 to 16.0 PSI||0.01||0.02 PSI||At 77.0 °F, 10.9 to 16.0 PSI|
|Monolithic silicon piezoresistive pressure sensor with second-order temperature correction. Maximum error over temperature range 32 to 158 °F (0 to 70°C) , +/- 0.06 inHg / +/-2.0 hPa. Calibration drift typically -0.03 inHg / -1.0 hPa per year. Pressure sensor may be recalibrated at factory or in field.|
|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.|
|°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.)|
|°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.)|
|°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.|
|One-button clear and restart of Max Wind Gust and Average Wind measurement.|
|Pressure Trend||Continuously updating three-hour barometric pressure trend indicator: rising rapidly, rising, steady, falling, falling rapidly.|
|Display||Reflective 4 digit LCD. Digit height 0.36 in / 9 mm.|
|Display Update||1 second.|
|Display Backlight||Aviation green electroluminescent backlight.|
|Clock / Calendar||Real-time hours:minutes clock.|
|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.|
|After 45 minutes of no key presses.|
|Certifications||CE certified. Individually tested to NIST-traceable standards (written certificate of tests available at additional charge).|
|Batteries||CR2032, one, included. Average life, 300 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 4.8 x 1.7 x 0.7 in / 122 x 42 x 18 mm. Case 4.8 x 1.9 x 1.1 in / 122 x 48 x 28 mm.|
|Weight||Unit 2.3 oz / 65 g. Case 1.3 oz / 37|