Measurement
Response Time |
Units |
Operational Range |
Resolution |
Accuracy
(+/-) |
Specification Range |
Wind Speed
(Air Velocity)
1 second |
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). |
Temperature
1 second |
°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. |
Relative Humidity
1 minute |
%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). |
Evaporation Rate
1 second |
lb/ft2/hr |
0.00 to 1.00 lb/ft2/hr |
0.01 |
Typical: ±0.02 lb/ft2/hr |
0.00 to 1.00 lb/ft2/hr |
| kg/m2/hr |
0.00 to 5.00 kg/m2/hr |
0.01 |
Typical: ±0.1 kg/m2/hr |
0.00 to 5.00 kg/m2/hr |
| Calculated
from the primary measurements of wind speed, air 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 with Kestrel 4300). For maximum
accuracy, readings should be taken 20 inches above pour surface with
the thermistor shaded, and averaged for 6-10 seconds using built-in
averaging function. Maximum accuracy: ±0.06 lb/ft2/hr or ±0.3 kg/m2/hr. |
Pressure
1 second (mb & PSI 4000 model only) |
inHg |
8.86 to 32.48 inHg |
0.01 |
0.05 inHg |
At 77.0 °F, <19,700 ft |
| hPa / mb |
300.0 to 1100.0 hPa / mb |
0.1 |
1.5 hPa / mb |
At 25.0 °C, <6,000 m |
| PSI |
4.4 to 16.0 PSI |
0.1 |
0.1 PSI |
At 77.0 °F, <19,700 ft |
| Monolithic
silicon piezoresistive pressure sensor with second-order temperature
correction. Maximum error beyond specified temperature, +/- 0.09 inHg
/ 3.0 hPa. Calibration drift typically -0.03 inHg / -1.0 hPa per
year. Pressure sensor may be recalibrated at factory or in field. |
Altitude
1 second |
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. |
Wind Chill
1 second |
°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.) |
Heat Index
1 minute |
°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.) |
Dewpoint
1 minute |
°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. |
Density Altitude
1 second |
ft |
-49.0 to 257.0 °F, 0.0 to 100.0 % RH, 8.86 to 32.48 inHg |
1 |
246 |
32.0 to 100.0 °F, 5.0 to 95.0 %RH, 8.86 to 32.48 inHg, <19700 ft |
| m |
-45.0 to 125.0 °C, 0.0 to 100.0 %RH, 300.0 to 1100.0 hPa |
1 |
75 |
0.0 - 37.8 °C, 5.0 to 95.0 %RH, -2000 to 9000 hPa, <6000 m |
| Calculated
from the primary measurements of temperature, relative humidity and
pressure. Air density converted to equivalent sea level elevation at
the International Standard Atmosphere. |
| Max/Avg Wind Speed (Air Velocity) |
One-button clear and restart of Max Wind Gust and Average Wind measurement. |
| Data Storage / Display |
Minimum,
maximum, average and logged history stored and displayed for every
measured value. 1800-point data logger with graphical display. Auto
data storage; interval settable from 2 seconds to 12 hours. Manual data
capture. |
| Data Upload |
Requires optional PC interface (NK PN-0830) and provided software. RS-232 connection with USB adapter available. |
| Display |
Multifunction, multi-digit programmable dot-matrix display. |
| Display Update |
1 second. |
| Display Backlight |
Aviation green electroluminescent backlight. Automatic or manual activation. |
| Clock / Calendar |
Real-time hours:minutes:seconds clock, calendar, automatic leap-year adjustment. |
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. |
| Auto Shutdown |
User-selectable: 15 or 60 minutes with no key presses or disabled. |
| Languages |
English, French, German, Italian, Spanish. |
| Certifications |
CE
certified. Individually tested to NIST-traceable standards (written
certificate of tests available at additional charge). |
| Batteries |
AAA Alkaline, two, included. Average life, 400 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 5.0 x 1.8 x 1.1 in / 12.7 x 4.5 x 2.8 cm. |
| Weight |
Unit 3.6 oz / 102 g. |