Accurate measurement

Observation of Vorticity Related Flux - Turbulent Aerodynamics Study

outline

CampbellofCSAT3The three-dimensional ultrasonic anemometer is a star instrument for measuring three-dimensional ultrasonic wind speed in the field of turbulent aerodynamics research. Based on the concept of integrating aerodynamics and its structural characteristics, and using ultrasonic pulse physics as its measurement principle, it is a three-dimensional anemometer that meets the technical process requirements for normal measurement under harsh weather conditions. It has low interference with the measured air and is durable. have10The centimeter vertical measurement path can output three-dimensional orthogonal wind speed and ultrasonic temperature. The maximum output frequency is50HzThere are two output modes: analog and digital.

Can receive any of the following three instructions to start and runSynchronous measurement instructions in data collectors（SDM）CSAT3Internal clock setting instructionsadoptRS-232Serial communication, usingPCGive instructionsuseSDMThe communication protocol can support the synchronous measurement of multiple or multiple groups of sensors. Advantages and Characteristics

ØThe innovative design provides accurate measurement of turbulence while reducing interference to the measured fluid itself.

ØInfrared CO with EC150 or EC155₂/H₂The O gas analyzer is integrated into a measurement system for measuring vorticity related fluxes in almost the same space.ØFully compatible with Campbell data collectorØMeasurement can be used to calculate momentum flux and friction velocity.ØCampbell microfilament thermocouple instantaneous reaction temperature sensor (e.g. FW05) can be assembled for measuring sensible heat flux.ØCan be applied in adverse weather conditionsØRainproof: The innovative combination of ultrasonic signal processing and audio transmitter receiver head with water absorbing and rainproof mesh effectively improves operation under rainy and cloudy conditionsQuality.ØSealed ultrasonic sensors and electronic control boxes. performance index

measure

ØOutput three-dimensional orthogonal wind speed [u_x， u_y， u_z(ms^-1）]And ultrasonic temperature [Ts (℃)] or sound velocity [c (ms)^-1）].ØThe sound velocity is measured from the sound path between each pair of ultrasonic sensors, with a total of three measurement paths. Corrected the influence of crosswind.ØMeasurement frequency: 100Hz, programmable settingØOutput bandwidth: 5, 10, 12.5, 20, or 25 HzØOutput frequency: 10, 20, 25, or 50 Hz Standard Error RMS^aØu_x， u_y： 1 mms^-1Øu_z： 0.5 mms^-1Øc：15 mms^-1（0.025℃） Accuracy^bØQuiet Wind u_x， u_y：＜ ±8.0 cm s^-1

u_z：＜ ±4.0 cm s^-1

Øslope error

The angle between the wind vector and the horizontal plane is within ± 5 °<>The angle between the wind vector and the horizontal plane is within ± 10 °<>The angle between the wind vector and the horizontal plane is within ± 20 °<> signal output

Digital SDM

CSI serial interface, used for communication between data collectors/sensors.Complete synchronization during group triggered event executionDigital RS-485Baud rate: 1200-230400 bpsData type: ASCII floating pointOutput frequency: 10, 25 or 50 HzUSBData type: ASCII floating-point numberOutput frequency: 10, 25 or 50 Hz

Output range

SDM and RS-485 digital outputs
Wind speed range: ± 65.535 m s-1
Sound velocity: 300~366 m s-1 (-50 ℃~+60 ℃)

Appearance description

Measurement path: Vertical: 10.0 cm; Horizontal: 5.8 cm
Measure the angle between the path and the horizontal plane: 60 °
Diameter of sound wave transmitter and receiver sensor: 0.64 cm
Sensor installation arm diameter: 0.84 cm
Supporting arm diameter: 1.59 cm
three-dimensional
Ultrasonic anemometer: 47.3 cm (l) x 42.4 cm (h)
Electronic control box: 26 cm x 16 cm x 9 cm
weight
Ultrasonic anemometer: 1.7 kg
Electronic control box: 3.8 kg
Material Science
Ultrasonic anemometer: stainless steel tube
Electronic control box: cast aluminum
Operating environment
Normal operating temperature range:- 30℃~+50℃
Power Supply
Voltage: 10~16 V DC
Current: 200 mA (when measuring frequency at 60 Hz)
100 mA (when measuring frequency at 20 Hz)

Schematic diagram of ultrasonic anemometer

Top view of the spatial structure of the three ultrasound probes below

^aRMS is calculated based on stable wind speed measurement data. The measurement frequency does not affect the resolution.
^bThe accuracy index of CAST3 three-dimensional ultrasonic anemometer refers to the temperature range of -30 ℃ to+50 ℃; When the wind speed is less than 30m s-1= The angle between the wind and the direction of the ultrasonic anemometer is greater than 30m

Origin: Campbell Corporation, USA