On-axis Accuracy: +/-3% of reading or +/-least significant digit, whichever is greater.
Off-axis Response: -1% @ 5 °, -2% @ 10 °, -3% @ 15 °.
Calibration Drift: <2% after 100 hours operation at 7 M/S
Minimum Speed: 0.3 M/S (~0.6 KT, 1KM/H, 0.7 MPH, 60 FPM).
Maximum Speed: 40 M/S (~78 KT, 144 KM/H, 89 MPH, 7830 FPM). Some loss of accuracy from bearing wear may occur with sustained operation over 25 M/S.

Display Specifications

Operating Modes: Moving three second average (wind speed), average since power on (AV) or maximum three second gust since power turned on (MAX).
Type: Reflective LCD.
Digit Height: 10 mm (0.4 in.).
Update: 1 second.
Range: 0.0 to 19.9, 20 to 199.
Units: Knots (KT), meters per second (M/S), kilometers per hour (KM/H), miles per hour (MPH) or feet per minute (FPM).

Operation Specifications

Buttons: Two sealed tactile rubber buttons control all functions.
Auto Shutdown: 30 minutes after last key press.
Battery: User-replaceable CR2032 coin cell. Typical life, 400 hours.

Environmental Specifications

Sealing: Electronics enclosure IP67 - water resistant to 1meter (3feet). Unit floats.
Shock: Drop tested to 2meters (6feet).
Temperature: Operating range -15 °C to 50 °C (5 °F to 122 °F). Storage range -20 °C to 80 °C (-4 °F to 176 °F).

Physical Specifications

Impeller: Diameter 25mm (1in.). High precision jewel bearings. User replaceable impeller assembly.
Case: Slip-on hard case protects display, buttons and impeller.
Dimensions: Unit, 122 x 42 x 14 mm (4.8 x 1.7 x 0.6 in.); case, 117 x 46 x 19 mm (4.6 x 1.8 x 0.7 in.); lanyard, 0.5 m (10 in.).
Weight: Unit, 43 grams (1.5 ounces); case, 23 grams (0.8 ounces).