Portable AVM-303 Wind Anemometer / Wind Speed Meter Product Features: 1.Sensitive and Accurate 2.Ergonomic and easy-to-use design 3.Large 4 digits LCD (Liquid Crystal Display) 4.1.8 meters coiled cable and mounting nut for long extension 5.Low power consumption 6.Hold/Max/Min/Ave functions 7.Build-in low battery indicator 8.Smart Auto-Power-Off (10 minutes) 9.USB Interface with PC (AVM-303) Electrical Specifications: (23C 5 C) Range of Wind Velocity:       Units    Range    Resolution    Threshold    Accuracy        m/s    0.0 - 45.0    0.01    0.5    3% 0.3        ft/min    0 - 8800    0.01/0.1/1    60    3% 40        knots    0.0 - 88.0    0.01/0.1    0.6    3% 0.4        Km/hr    0.0 - 160.0    0.01/0.1    1.0    3% 0.8        mph    0.0 - 100.0    0.01/0.1    0.7    3% 0.4     m/s: meter per second ft/min: feet per minute knots: nautical miles per hour Km/hr: kilometers per hour mph: miles per hour Unit Conversion table:           m/s    ft/min    knots    Km/hr    mph        1 m/s    1    196.87    1.944    3.60    2.24        1 ft/min    0.00508    1    0.00987    0.01829    0.01138        1 knot    0.5144    101.27    1    1.8519    1.1523        1 Km/hr    0.2778    54.69    0.54    1    0.6222        1 mph    0.4464    87.89    0.8679    1.6071    1     General Specifications:       Mounting Nut:    1/4" x 20        Operating Temperature:    Meter: 0 C ~ 50C (32 F ~ 122F) Vane: 0C ~ 60C (32 F ~ 140F)        Operating Humidity:    Less than 80% RH        Operating Pressure:    500 mB ~ 2 Bar        Storage Temperature:    -10C ~ 60C (-40F ~ 140F)        Power Consumption:    Approx. 6 mA        Battery Type:    1.