App & wind meter

How do I get the true wind speed?

Ultrasonic: by using the compass, GPS and accelerometer within the phone and the wind meter we can calculate the true wind speed. Handheld devices measure only the apparent wind speed.

Can I export data from the Vaavud app?

No, at the moment it is not possible, but might become a feature in the future.

Will the app be able to measure wind direction?

Ultrasonic: measures both wind speed and wind direction.

Mjolnir: measures wind speed

Sleipnir measures wind speed and wind direction

How long does it take to measure the wind?

With both the Ultrasonic and the handheld wind meters you need a measurement of at least 30 seconds.

What is the gust value?

For each measurement a gust value is calculated. The gust value tells you how much the wind is varying relative to the wind speed. A low value below 10% is a very steady wind while a high value above 30% means the the wind is varying a lot.

The technical term is turbulence intensity and is explained here.

Will the windmeter work with a bumper/cover/case?

The Ultrasonic works with Bluetooth, and has no issues with cases. The Mjolnir wind meter works with most standard bumpers/covers. If the cover is too thick (more than 3mm, e.g. Lifeproof for iPhone 5) then the wind meter will not sit tight in the jack stick, but it can still transmi signal to the phone.

The **Sleipnir **wind meter is specifically designed to work with a wide range of bumpers up to 8 mm thick/high. If the cover is very thick on the backside, then it is possible on iOS to change the clip orientation in settings to a front-facing mode. We have successfully used Sleipnir together with Lifeproof FRĒfor iPhone 5/5S, but there have been reported issues with the Nuud case. If you are unsuccessful in using a case with Sleipnir, please notify us on social media or

Why is the chill factor not displayed?

After a measurement has been taken we display the wind chill. We use the North American and United Kingdom wind chill index.

Please note that a wind chill temperature is not defined for all weather conditions:

Windchill temperature is defined only for temperatures at or below 10 °C (50 °F) and wind speeds above 4.8 kilometres per hour (3.0 mph).

Therefore the app will sometimes display a “-” instead of a value.

What is the operating range and precision of the wind meter?

Ultrasonic: wind rage 1-25 m/s with +/- 1% accuracy. The wind range of Mjolnir is 2-20 m/s, and the wind range of Sleipnir is 2-40 m/s, both with +/- 4% precision.

Android devices "no signal" message while measuring

Some of our Sleipnir from the first production batch have a relatively short audio plug, on certain phones this can cause connection problems. The app will show “device disconnected” before removing the device or “no signal” when measuring.

Usually, this can be fixed by pressing the wind meter into the plug very hard. If this does not solve the problem, get in touch with u s on social media or

Will you be able to choose the unit of measurement?

On the measurement screen in the Vaavud app, press the unit icon until is shows your preferred unit of measurement (m/s, mph, kt, bft or km/h).

Can I delete a measurement?

You can delete your measurements. Deleted measurements will be deleted from your history and not show on the map. Here is how to do it:

  • iOS: In the history list swipe the measurement you want to delete to the left and press “Delete”.
  • Android: In the history list log press the measurement you want to delete. Press delete in the popup option menu.

What is the weight of just the device?

Ultrasonic: 130 grams. Mjolnir weighs 17 grams, and Sleipnir 14 grams.

Will the measurement be influenced by movement?

When measuring true and apparent wind speed and wind direction with the Ultrasonic we also consider pitch and tilt.

How do I mount my Ultrasonic?

The Ultrasonic has a 16 mm Female thread which should be used for mounting.

How do I connect to the Ultrasonic?

Press the button in the app to start a measurement to connect to your Vaavud Ultrasonic. You cannot establish connection through the phone / tablet settings.

Where do I mount the Ultrasonic?

The best solution is on top of a mast or similar. Please make sure there is no is immediate objects interfering with the wind flow.

How do I charge my wind meter?

Ultrasonic: leave it under a bright lamp for a few hours. Handheld does not require any charging.

Can I mount the Ultrasonic on a rotating mast?

At the moment, we do not support rotating masts?

How long battery life do the devices have?

Ultrasonic: More than 1 year not measuring and 30 days measuring. Handheld does not include batteries.