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The TriSonica Mini provides an extensive Help Menu accessible simply by typing ‘help’ at the Command Line.

The TriSonica Mini uses the same principles of physics as other ultrasonic anemometers: that is, mathematically deriving atmospheric conditions from the detected difference in time-of-flight for sound transmitted bi-directionally along the same acoustic pathway.
A single bi-directional acoustic pathway allows for deriving wind speed. Data from two bi-directional acoustic pathways can provide both wind speed and two-dimensional wind direction. As explained by Dr. J. Chandran Kaimal, the originator of acoustic anemometry, a three-dimensional wind direction solution be calculated by using three or more bi-directional acoustic pathways. The challenge in obtaining three or more bi-directional acoustic pathways is creating a structure for the sound-generating transducers with minimal perturbation of the air flow to be measured. The “other 3-D anemometers” your customer mentions are likely the Orthogonal-style (Applied Technologies: producer of the original commercially available 3-D ultrasonic anemometer) and the Oncley Non-orthogonal-style (Applied Technologies, R.M. Young, Gill Instruments, Campbell Scientific, and others). These anemometers use six transducers creating three bi-directional acoustic pathways, and solve the problem of transducer support structure by placing the sound-generating transducers on long thin probe arms. Following careful wind-tunnel studies, these units rely on software-based correction of structure- and transducer-shadowing effects. The size of the probe arms on these devices means that these anemometers are generally heavy and bulky.
Stephen Osborn, the principal engineer behind the TriSonica Mini, worked for many years with Applied Technologies in designing, developing, improving, and programming their historically significant line of ultrasonic anemometers. It became apparent to him that the growing field of UAV-based weather sensing would benefit from a smaller and lighter multi-dimensional ultrasonic anemometer. With permission from Applied Technologies, Mr. Osborn began independently working on a smaller design that would eventually become the patented TriSonica Mini anemometer.
The TriSonica Mini is able to scale down size because it features fewer transducers to produce four bi-directional acoustic pathways arranged in a tetrahedral configuration, similar to an idea first put forth by researchers at Woods Hole Oceanographic Institute for underwater current turbulence sensing. The TriSonica Mini’s four acoustic pathways cross the wind path generally outside the structure of the probe itself, allowing for wind detection in 3 dimensions; and ongoing wind-tunnel study allows for continued refinement of shadow-correction software (resulting firmware updates are made available for download by TriSonica Mini users at the Anemoment.com website). However, in the TriSonica Mini detection of the third-dimension (up-down) component of wind is limited due to the effect of the top and bottom structures to about 30 degrees from the horizontal, making it imperfectly suited for use as a flux-measurement system. An improved design is under development which is expected to overcome this limitation.

The TriSonica Mini and TriSonica Sphere provides precise wind speed and direction by measuring a combination of three axis of air flow (U, V, and W).

If you need a vertical wind measurements, you need the TriSonica Sphere Wind Flux Sensor. The TriSonica Sphere was specifically engineered to deliver precise vertical wind measurements. Its unique spherical design (patent pending) dramatically reduces shadow correction while increasing the accuracy of vertical wind measurements.

The current iteration of the TriSonica Mini has a +/- 15 degree angle of acceptance of vertical measurement before the shadowing effects of the mounting structure becomes noticeable, therefore it is not capable of measuring atmospheric flux.  On the other hand, the TriSonica Sphere, with its unique patent pending spherical design, was specifically engineered to deliver precise vertical wind measurements coupled with fast sampling rates (up to 100 Hz) making it ideal for atmospheric flux and turbulence research. To ensure that you hear about the latest releases or announcements from Anemoment, LLC, subscribe to our newsletter. 

Both the TriSonica Mini and TriSonica Sphere are weather resistant. For the flat-based version of the TriSonica Mini, you need to make sure that the seal around the wires in the center is in good condition. The Gore-Tex vent (the white dot) on the bottom also needs to be in good condition and should be facing down when installed. The vent is an adhesive sticker, so it cannot withstand a stream of water. The connector on the Pipe-Mount version (both TriSonica Mini and TriSonica Sphere) is an IP-67 connector when mated with the cable and is usually inside the mounting tube. Neither instrument should be submerged.

The TriSonica Mini is able to measure accurately when tilted (up to a 15° tilt), such as on a UAV or buoy.

The TriSonica Mini Wind & Weather Sensor is constructed of DuPont™ Zytel^®nylon resin. Zytel 80G33HS1L is a 33% glass fiber reinforced heat stabilized polyamide 66 resin engineered for demanding applications where outstanding impact resistance, high mechanical strength, stiffness and extreme temperature performance are required (learn more here).

The TriSonica Sphere Wind Flux Sensor’s all-aluminum construction enhances the devices’ durability while maintaining its SWaP (Size, Weight, and Power) advantage over competitive sensors.

Both the TriSonica Mini Wind & Weather Sensor and the TriSonica Sphere Wind Flux Sensor can operate in temperatures ranging from -40C to 85C.

The body of the TriSonica Mini is injection molded of glass-infused nylon supported by carbon-fiber rods, well suited for exposure to extreme environmental conditions, and which weathers to a pleasant gray patina while retaining structural integrity. The TriSonica Mini has been thermal chamber tested, confirming that the device can operate at conditions down to -50C, and can transition from an off state to on state after cold soaking at -40C. The electronics aboard the TriSonica Mini anemometer bear specifications for use up to 85C, but we have had no use cases that operate above about 65C.

As for humidity, of course a thoroughly soaking heavy rain or snow (100% humidity) will block the acoustic pathway between transducers, but the interior electronics continue to function. The humidity sensor is located on the interior of the TriSonica Mini, and air flows to it through a Gore-tex vent positioned to prevent incursion of liquid water on the electronics. The device is capable of operating in high humidity environments; however if a hot, high humidity environment suddenly transitions to a cold environment, the water vapor inside the TriSonica Mini may condense, resulting in a humidity sensor reading higher than 100% until the condensate evaporates and transpires through the vent.

The TriSonica 3D Sensors both output an ASCII string that can easily be store to a text file. We use a program called TeraTerm and it provides a logging function that will write the data into text file. It is then very easy to import the text file into Excel for processing.  We are working on a Windows Graphical User Application that also has logging capability.

The TriSonica Mini – Flat Base supports RS-232 digital output, while the TriSonica Mini – Pipe Mount and the TriSonica Sphere both support  RS-232, RS-422, and UART-3V digital outputs.

The height of the anemometer position is dependent on what you are trying to study. We have seen some installations that mount the TriSonica Mini a few inches above the beach/rocks and others that put it on 3 to 10 meter towers.

If you intend to mount the TriSonica Mini or TriSonica Sphere on a multi-rotor UAS or drone, we recommend a minimum height above the rotor plane of 500 mm or 1.5X the rotor diameter, whichever is greater.

Researchers at the International Conference on Unmanned Aircraft Systems (ICUAS) have reported that influences from rotors are negligible at around 400 to 450 mm above the aircraft’s rotor plane. Our customers have mounted their TriSonica Mini as high as 18″ to 20″ above the rotor plane to negate any impact the blades might have on their readings.

If you are interested in measuring the wind speed at on a island, then we suggest that you put the TriSonica Mini high to avoid the turbulence caused by the island topology. The size of those island features will have an effect on how high you need to be. The higher you go the less of an effect the island will have on the airflow.

Available in a pipe-mount version, installation is simplified and streamlined. Will accommodate any 1/2″ schedule 10 pipe.

ICUAS Research: T. S. Johnansen, A. Cristofaro and K. Sorosensen, “On estimation of wind velocity, angle-of-attack and sideslip angle of small UAVs using standard sensors,” 2015.

The TriSonica Mini operates on an input voltage of 9V to 24V and requires about 360mW to operate. You can power the TriSonica Mini via a solar panel as long as the panel and battery pack produces a minimum of 12V.

The four wires coming out of the TriSonica Mini are:

• Yellow – 9-36V (you will need to supply this power separately)
• Red – RS-232 TXD (data out of the TriSonica Mini)
• Green – RS-232 RXD (data into the TriSonica Mini)
• Black (Ground)

Our USB Interface Adaptor translates the RS-232 signals from the TriSonica Mini to a USB connection, and converts the USB 5V to 12V to power the TriSonica Mini directly. With the USB Interface Adaptor in place, a separate power supply is not necessary providing a single cable connection between a PC and a TriSonica Mini.

Anemoment LLC fulfills all orders from our corporate headquarters in Colorado, USA. If you have an account with an international shipping company that you would like us to use to ship your order, please provide that information at the time you place your order. Otherwise, we will use the United States Post Office or UPS for all order fulfillment. Shipping options and associated costs are displayed and are selected by the customer at time of order.

The User Manuals for the TriSonica Mini family of products can be found near the top of this page under Downloads. The User Manuals available on the website may not match your unit exactly because the TriSonica Mini is configurable to add and remove fields to the user’s needs. The “display” command lists all of the fields and prints a table of what is enabled for display. You can turn outputs on and off, but you cannot change their order.

Firmware Release 1.9.0 (December 2019) is now available. It is recommended that all TriSonica Mini users update the firmware on their devices to Firmware Release 1.9.0. Firmware Release 1.9.0 provides a number of improvements designed to enhance your experience with your TriSonica Mini. Enhancements include:

• Added Low Power Mode with internal and external wakeup. External wakeup should only be used with a Pipe-Mount version.
• Modified data output tags to make them unique. Eliminating multiples Ps and Ds
• Fix the bug where the temperature and humidity can get stuck outputting ‘nan’
• Rewrote the humidity calculations to use partial pressures to determine molar mass. The calculations are no longer dependent on the previous temperature reading.
• The calibration command was modified to accept a pressure value so that a more accurate value of molar mass can be calculated for determining the speed of sound.
• Fixed long help for show, hide, decimals, tag, untag to display properly
• Fixed Display and Decimals commands to show and set Humidity and Pressure decimals.
• Added trisonicaid command to allow users to identify data streams from multiple instruments.

1) Connect to your TriSonica Mini on the Settings page. 2) Click the browse button and find files on your computer. 3) Click the Update Button and the update begins. 4) Wait for the update to complete.

NOTE: Devices with Firmware Release 1.5.2 need to contact Anemoment directly in order to arrange for their device to be brought current with Firmware Release 1.74. The update process described above will not update these units.

Firmware Updates can now also be found near the top of this page under Downloads.