The Model 81000 R. M. Young Ultrasonic Anemometer is a three-dimensional no-moving-parts wind sensor. Two-dimensional anemometers meet the need for economy, but they ignore the important vertical wind component. The 81000 measures three dimensional wind velocity based on the transit time of ultrasonic acoustic signals. From speed of sound, sonic temperature is derived. Speed of sound and sonic temperature are corrected for crosswind effects. Measurement data are available as voltage output signals or serial output using RS232 or RS485 connections. Both voltage and serial output may be configured for various output formats. Operating parameters may be edited using ordinary terminal software on a PC. Simple menus make it easy. All parameters are stored in nonvolatile memory. The sensor features robust construction with three opposing pairs of ultrasonic transducers supported by stainless steel members. This arrangement provides rigidity to the anemometer while offering a measure of protection to the transducers. The transducers are arranged so that measurement are made through a common volume, thereby improving the validity of the measurement. A fast 160 Hz sampling rate ensures superior measurement resolution. Superior environmental resistance is achieved by using UV stabilized thermoplastic, stainless steel, and anodized aluminum components. Electrical connections are made via an easily accessible junction box. The unit mounts on standard 1" pipe. Specifications Operating Temperature -50 to +50 °C Range Wind speed: 0 to 40 m/s (0 to 90 mph) Resolution: 0.01 m/s Threshold: 0.01 m/s Accuracy: 1% rms 0.05 m/s (0 to 30 m/s) 3% rms (30 to 40 m/s) Wind direction: 0 to 360 degrees Elevation range: 60 degrees Resolution: 0.1 degree Accuracy: 2 degrees (1 to 30 m/s) 5 degrees (30 to 40 m/s) Speed of sound: 300 to 360 m/s Resolution: 0.01 m/s Accuracy: 0.1% rms 0.05 m/s (0 to 30 m/s) Sonic temperature: -50 to +50 °C Resolution: 0.01 °C Accuracy: 2 °C (0 to 30 m/s) Serial Output RS232 or RS485 1200 to 38400 baud 4 to 32 Hz (user-selected) User programmable ASCII output configuration (select from U, V, W, Speed of sound, Sonic temperature, 2D speed, 3D speed, Azimuth, Elevation) Preset outputs: NMEA- Marine Standard RMYT- Wind Tracker Units: m/s, cm/s, MPH, Knots, Km/hr Analog Voltage Outputs 4 voltage outputs, 0 to 4000 mV (select from U, V, W, Sonic temperature or Speed, Azimuth, Elevation, Sonic temperature) Power Requirement 12 to 30 Vdc, 4 watts Dimensions 56 cm high x 17 cm radius (3 support arms) Weight/Shipping: 1.7 kg (3.8 lb)/4.5 kg (10 lb)