TASI TA642B Digital Anemometer Handheld Wind Speed Meter Measuring Air Flow Speed Wind Temperature LCD Backlight Display Features: Air Velocity/Air Temperature/Air Flow: Multiple functions, it can be switched between different measurement units. 8 Fan Blades: 8 fan blades design, with low friction and high precision bearings, high-sensitive response. Prompt When Over Upper/Lower Limit: The upper and lower alarm limit can be set separately. When over upper/lower limit, there will be a buzzer alarm sound, and the alarm indicator light will flash. Data Storage: It can record and store 1000 groups data; TA642B/C can connect the PC through the USB to export the data records and generate charts. USB Connection (only TA642B/C): With data records download and real-time PC connection function, it can display real-time data sheet and real-time data charts. Dual Power Mode/Auto Power Off: Dual power modes: 3 x 1.5V AA (LR06) battery (not included) or USB power supply; Automatic power off after 15 minutes without operation (can be disabled). Specifications: Model: TA642A, TA642B, TA642C (Optional) Material: ABS Measurement Method: Intergral type (TA642A, TA642B); Split type (TA642C) Air Velocity: Range: 0.06-45.0m/s Accuracy: ±(2%+0.2) Resolution: 0.01/0.1/1 Air Temperature:  Range: 0℃~45℃ (32℉~113℉) Accuracy: ±2℃ (±3.6℉) Resolution: 0.1/1 Display: 4 digits, max 9999 Sensor: Infrared laser tube cutting method Sampling Rate: 2 times/s Repeated Test Deviation: ±2% Data Storage: 1000 groups USB Connection: No (TA642A), Yes (TA642B, TA642C) Auto Power Off: 15 mins (can be disabled) Working Enviroment: -10℃~50℃. Max 80%RH, indoor altitude＜2000m Storage Enviroment: -10℃~50℃. Max 70%RH (battery removed) Screen Size: 53 * 44mm Power Supply: 3 * 1.5V AA (LR06) battery (Not included), USB micro interface 5V Item Size: 239 * 70 * 35mm / 9.41 * 2.75 * 1.38in Item Weight: 210g / 7.41oz Package Weight: 550g / 19.40oz Package Size: 29.5 * 10 * 6cm / 11.61 * 3.94 * 2.36in Package List: 1 * Digital Anemometer 1 * USB Cable 1 * Cloth Bag 1 * User Manual (English)