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Kestrel 5500FW Fire Weather Meter Sensor Specifications

Sensor Specifications

 Wind Speed
Units of Measure: mph | kt | B | m/s | ft/min / km/h 
Specification Range:
  • 0.6 to 40.0 m/s
  • 118 to 7,874 ft/min
  • 2.2 to 144.0 km/h
  • 1.3 to 89.5 mph
  • 1.2 to 77.8 knots
  • 0 to 12 B*
  • 2-131.2 F/S*
Operational Range:
  • 0.6 to 60.0 m/s
  • 118 to 11,811 ft/min
  • 2.2 to 216.0 km/h
  • 1.3 to 134.2 mph
  • 1.2 to 116.6 knots
  • 0 to 12 B*
  • 2-196.9 F/S*
Resolution:
  • 0.1 m/s
  • 1 ft/min
  • 0.1 km/h
  • 0.1 mph
  • 0.1 knots
  • 1 B
Accuracy (+/-): Larger of 3% of reading, least significant digit or 20 ft/min
Notes: 1 inch|25 mm 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% @ 5º off-axis; -2% @ 10º; -3% @ 15º. Calibration drift < 1% after 100 hours use at 16 MPH | 7 m/s. Replacement impeller (PN-0801) field installs without tools (US Patent 5,783,753). Wind speed calibration and testing should be done with triangle on impeller located at the top front face of the Kestrel. *F/S only in Ballistics units. Beaufort not available in Ballistics units.

Ambient Temperature
Units of Measure: Fahrenheit, Celsius
Specification Range:
  • -20.0 to 158.0 °F
  • -29.0 to 70.0 °C
Operational Range:
  • 14.0.0 to 131.0 °F
  • -10.0 to 55.0 °C
Resolution:
  • 0.1 °F
  • 0.1 °C
Accuracy (+/-):
  • 0.9 °F
  • 0.5 °C
Notes: Airflow of 2.2 mph|1 m/s or greater provides fastest response and reduction of insolation effect. For greatest accuracy, avoid direct sunlight on the temperature sensor and prolonged sunlight exposure to the unit in low airflow conditions. Calibration drift is negligible for the life of the product. For further details, see Display & Battery Operational Temperature Limits.

Pressure
Units of Measure: inHg, hPA, mb
Specification Range:
  • 25°C/ 77°F
  • 750-1100 hPa|mbar
  • 22.15-32.48 inHg
  • 10.88-15.95 PS
Operational Range:
  • 0.30 to 48.87 inHg
  • 10.0 to 1654.7 hPa|mbar
  • 0.14 to 24.00 PSI
  • 14.0 to 131.0 °F -10.0 to 55.0 °C
Resolution:
  • 0.1 hPa|mbar
  • 0.01 inHg
  • 0.01 PSI
Accuracy (+/-):
  • 1.5 hPa|mbar
  • 0.044 inHg
  • 0.022 PSI
Notes: Monolithic silicon piezo-resistive pressure sensor with second-order temperature correction. Between 1100–1600 mbar, unit will operate with reduced accuracy. Sensor may not operate above 1600 mbar and can be damaged above 6,000 mbar or below 10 mbar. Calibration drift is negligible for the life of the product.

Relative Humidity
Units of Measure: %
Specification Range: 5 to 95% 25°C non-condensing
Operational Range: 0 to 100% 
Resolution: 0.1 %RH
Accuracy (+/-): 3%RH
Notes: 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 is typically less than ±0.25% per year.

Compass
Units of Measure:  Compass Heading in True or Magnetic
Specification Range: 0 to 360°
Operational Range: 0 to 360°
Resolution: 1° 1/16th Cardinal Scale
Accuracy: ±5°
Notes: 2-axis solid-state magneto resistive sensor mounted perpendicular to unit plane. Accuracy of sensor 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). Readout indicates direction to which the back of the unit is pointed when held in a vertical orientation. Declination/variation adjustable for True North readout.

Calculated Measurements

 Altitude

 
Accuracy (+/-):
  • typical: 23.6 ft/7.2 m
  • - 50 to 1100 mBar
  • max: 48.2 ft/14.7 m
  • – 300 to 750 mBar
Resolution:
  • 1ft
  • 1m
Sensors employed:
  • Pressure
  • User Input (Reference Pressure)

Dew Point
Accuracy (+/-):
  • 3.4 °F
  • 1.9 °C
  • 15-95% RH. Refer to Range for Temperature Sensor
Resolution:
  • 0.1 °F
  • 0.1 °C
Sensors employed:
  • Temperature
  • Relative Humidity

Wet Bulb Temperature - Psychrometric
Accuracy (+/-):
  • 3.2 °F
  • 1.8 °C
Resolution:
  • 0.1 °F
  • 0.1 °C
Sensors employed:
  • Temperature
  • Relative Humidity
  • Pressure

Wind Chill
Accuracy:
  • 1.6 °F
  • 0.9 °C
Resolution:
  • 0.1 °F
  • 0.1 °C
Sensors employed:
  • Wind Speed
  • Temperature

Density Altitude
Accuracy:
  • 226 ft
  • 69 m
Resolution:
  • 1ft
  • 1m
Sensors employed:
  • Temperature
  • Relative Humidity
  • Pressure
Sensors employed:
  • Temperature Relative
  • Humidity
  • Pressure

Heat Index
Accuracy:
  • 7.1°F
  • 4.0°C
Resolution:
  • 0.1 °F
  • 0.1 °C
Sensors employed:
  • Temperature
  • Relative Humidity

Probability of Ignition (PIG)
Accuracy:
  • PIG Accuracy dependent on proximity of inputs to reference table steps.
Resolution:
  • 10%
Sensors employed:
  • Temperature
  • Relative Humidity

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