USER MANUAL. Specifications. 0.1 m/s for wind speed degrees for wind direction -30 C to +80 C for temperature

Transcription

1 USER MANUAL Overview The TriSonica Mini is a lightweight three-dimensional airflow sensor in a small package, ideal for both fixed and moveable applications. TriSonica Mini uses the properties of sound waves to generate real-time threedimensional data on the wind speed flowing through and around the device in all directions. Small and lightweight, TriSonica Mini can be mounted in small spaces or on moving objects. The TriSonica Mini offers a single RS-232 serial data output, with the ability to display the information feed as wind speed and direction, or as the three wind vectors U, V, and W. Ambient temperature information may also be displayed. With the optional sensors package, TriSonica Mini can display humidity, absolute pressure, tilt, and magnetic compass heading. Specifications Range Resolution Accuracy Operating Temperature Digital Output Data Output Rate Operating Frequency Anemometer Power Dimension Weight 0-30 m/s for wind speed degrees for wind direction -30 C to +80 C for temperature 0.1 m/s for wind speed 1.0 degrees for wind direction ±1.0 C for temperature ±0.5 m/s for low range wind speed ±2% for high range wind speed ±1.0 wind direction ±2 C Temperature ±0.5 C Temperature with Humidity Sensor ±5% Humidity ±3 hpa Absolute Pressure ±1.0 Tilt for Pitch and Roll ±5 Magnetic Heading -30 C to +80 C RS-232 standard 1 Hz, 2 Hz, 5 Hz, 10 Hz 60 khz VDC, 12V 92.5mm x 92.5mm x 55mm 50 grams Page 1 of 7

2 Mounting Suitable for a variety of applications, the TriSonica Mini has four mounting points on its base for connection to a user-supplied mounting device. The user-supplied mounting device should be a flat plate having a 3-mm hole in the center. If the optional sensors are included, then the TriSonica Mini has a vent port that need to remain clear to allow water vapor and air pressure exchange. A drawing of the TriSonica Mini is at the end of this document. Orientation A north indicator N is marked on one of the upper arms of the TriSonica-Mini. Airflow going into the 'N', or flowing from north to south will return zero degrees for wind direction. Connecting TriSonica Mini provides four un-terminated wires for user hookup. is 12V to 24V. is RS-232 TxD. is RS-232 RxD. Black is Ground (and the serial connector return). Optional Sensors TriSonica Mini has an option to add humidity, absolute pressure, tilt, and heading. Humidity The humidity sensor is located inside the TriSonica Mini and depends on the water vapor transfer membrane to keep the humidity inside the same as outside the unit. This causes a delay in the humidity reading when the humidity changes rapidly. This delay can be up to an hour for very large humidity changes, such as moving the unit from a 90% environment to a 40% environment. Normal environmental humidity changes that happen more slowly should experience a much quicker latency. Another issue seen during testing happened when the TriSonica Mini was removed from a warm 90% humidity environment to a cooler 40% environment. The quick change caused condensation inside the unit and it displayed humidity greater than 100% and did not return to normal measurement until the condensation evaporated and passed through the vent. Page 2 of 7

3 Absolute Pressure The absolute pressure sensor is located inside the TriSonica Mini and depends on the water vapor transfer membrane to keep the pressure inside the same as outside the unit. Tilt The accelerometer is located inside the TriSonica Mini. Since the mounting of the TriSonica Mini will affect the tilt measurement, the offsets have not been set during manufacturing. A calibrate tilt command is provided so the TriSonica Mini can subtract the offsets from the measurement to set the level. The raw accelerometer outputs are also available. Compass The magnetic sensor is located inside the TriSonica Mini. Since the heading reading of the magnetic sensor is very dependent on the magnetic effects of the environment around it, the heading is not calibrated during manufacturing. A calibrate compass command is provided to adjust the heading. To calibrate the heading, the user invokes the command and then rotates and tilts the unit. This process is similar to how you calibrate the compass of your handheld devices. Output is Configurable The data output is an ASCII character string ending with carriage return and line feed characters. Each line is a single record. One or two spaces, or a single space and a negative sign separate each value on the line. An optional data tag indicates the measurement associated with the value and can be turned on or off for each individual measurement. A sample of the default output without tags: The columns in this example in order are Wind Speed, Wind Direction, U (North-South) Vector, V (West-East) Vector, W (Up-Down) Vector, and Temperature. A sample of the output data with tags: S 05.2 D 112 U V 04.7 W 01.1 T 22.6 S 05.3 D 107 U V 04.9 W 01.3 T 22.2 S= Wind Speed D= Wind Direction U= North-South Vector V=West-East Vector W=Up-Down Vector T=Temperature Page 3 of 7

4 Display Command The display command prints a table indicating the name and description of each signal available, whether it is tagged or not, what the tag value is, how many decimals are displayed, whether the signal is enabled to be added to the serial output string, and the units for each measurement. Show, Hide, Tag, Untag, and Decimal Commands The show, hide, tag, untag, and decimal commands operate similarly. They enable a measurement, disable a measurement, display the tag for a measurement, remove the tag for a measurement, or adjust the number of decimals for an output; respectively. When invoked without a parameter, they display the options available. The show command only lists the values that are available to be enabled, similarly the hide command only lists the values that are enabled that can be hidden. (The hide command provides a convenient list of all values currently being displayed.) The tag and untag commands show only the values available to be tagged and untagged, and the decimal command only lists the values that allow changing their decimal resolution. Serial Commands The default serial configuration for TriSonica Mini is ,8,N,1. TriSonica Mini starts generating data one second after power up, and outputs data continuously when in sampling mode. Use Ctl+C to enter the command line interface (CLI). CLI mode stops sampling, and provides a user prompt: >. Details of all available commands and their parameters are accessed within the Command Line interface by typing help at the user prompt. For reference, some of the commands are also listed below. Parameters and commands shown within square brackets [ and ] are optional. The detailed help for each command supersedes the information in the following table. COMMAND Help help <command> exit baudrate [<baud> [now]] DESCRIPTION Displays a list of all CLI commands. The command word help followed by the name of another command displays detailed help for that command. Leave the CLI and return to sampling. Show or set the current baud rate Page 4 of 7

5 calibrate <temp> [<rh>] compasscalibrate YES display [<param> <command>] hide [<param>] levelcalibrate YES nvwrite outputrate [<value>] parity [odd even none [now]] programupdate [YES] show [<param>] systemreset tag [<param>] untag [<param>] version wd540 [<value>] Start a calibration cycle Calibrate the Compass by waving and rotating the unit in all directions. (Only available if compass sensor is installed.) Show the current Display Mode settings Hide Display Parameter Groups Calibrate the Level while on a known level surface. (Only available if accelerometer is installed.) Writes parameter data to non-volatile memory Set or Show the data output rate of the sampled data Set or Show the current parity setting Starts a ymodem session to download new firmware. Show Display Parameter Groups Software Reset. Display the ID Tag of a Display Parameter or a Group of Parameters Remove the ID Tag of a Display Parameter or a Group of Parameters Displays software version and build numbers Set or Show the Wind Direction 540 Degree Mode Calibration Command Place the probe inside a small container that will reduce the airflow to as close to zero as possible, but acoustic reflections must also be reduced. The small box and foam liner that the TriSonica Mini was shipped in is good. Type calibrate <temp> [<rh>] Where the <temp> = xx.x in C temperature and <rh> = xx.x in % relative humidity. If humidity is not supplied, then 50% is assumed. The calibration cycle takes ten seconds. You will see dots printed on the serial console indicating progress, and the serial prompt will return. Then type nvwrite to store the values in non-volatile memory. Page 5 of 7

6 Wind Direction Scale Command (wd540) Wind direction can be displayed in a traditional 0 to 360 degree format or in a 0 to 540 degree format for strip chart type displays. The 540 degree mode prevents full scale shifting of data when the wind direction is around 0, when it moves from 359 to 0 to 359. The data makes a single large transition once at 540 degrees and again at 180 degrees to display data otherwise. Wind Tunnels Ultrasonic anemometers operate using ultrasonic pulses and measuring the time of flight between transducers. The time of flight measurements can be disturbed by external noise sources in the same frequency band that the ultrasonic anemometer operates within. Some wind tunnels generate ultrasonic noise that can cause erroneous readings from the anemometer. This is not an indication of failure of the anemometer, but an artifact of using the anemometer in an ultrasonically noisy environment. Compact Florescent Lamps Many compact florescent lamps operate at ultrasonic frequencies and can interfere with the operation of a TriSonica Mini. If the instrument is operated near any compact florescent lamps, erroneous and erratic readings will result. Turning off the compact florescent lamps should result in proper instrument operation. Page 6 of 7

7 TriSonica Mini Mounting Page 7 of 7