3. Getting started

1. Buy a CR2032 coin cell battery for the head sensor.

2. Download ACT Head Impact Tracker smartphone mobile App from Google Play on your smartphone. Please notice that App is for Android 9 or newer Android operating system only, and that the App’s compatibility with all and every smartphone brand and model has not been tested and cannot be guaranteed. Updated list of brands and models tested can be found in FAQ in www.act-tracker.com

3. Create User Account in the App. Your email acts as your User-ID. Make sure to store your password somewhere safe.

4. Create Profile in your User Account to which you want to add the head sensor to. Follow App’s instructions on creating Profile. Please note: You cannot remove or change Profile once created.

5. Ensure location services and Bluetooth® wireless communication are enabled, on and active in your smartphone for the App and always when using it with the head sensor. Ensure also that your mobile data and roaming (if needed) are enabled, on and active in your mobile device for the App and always when using it with the head sensor, or that you are connected to Wi-Fi. If you do not have mobile data or Wi-Fi at your disposal, please use the sensors in Tracker mode, it will decrease their power consumption. Note: when sensors are on Tracker mode, near-real-time delivery of sensor measurements is not functional, you have to download the impacts from the sensor to the App after the session, when mobile device can be connected to mobile data or Wi-Fi.

6. Remove the head sensor from its package. Open the hatch. Add the coin cell battery by carefully sliding it underneath the silver-colored holder bridge as indicated by the arrow on the bridge + side is facing you and away from the electronics.

7. Locate the head sensor’s Serial number also acting as Registration code, which is on the product label underneath the battery hatch. Open the hatch and you can see the white sticker on the lid. Registration code is a 6-digit code on the product label.

8. Close the hatch by pressing all the sides firmly together to seal the locks on them. Check that the sides are seamlessly connected with each other before the use. Please note: Inserting the battery may turn the sensor on, but some components might not turn on. Before the use, switch the sensor off and back on.

9. Turn the head sensor on by pressing the on/off-button once slowly and firmly. The sensor is on when the small red led light next to the button starts to blink in slow frequency.  If the led-light blinks in high frequency (in fast pace), the battery is almost empty. Change the battery or ACT Head Impact Tracker might not work as intended. If the light does not come on at all, or the light comes on but it is not blinking, try with a new battery. If the light still is not coming on at all, or the light comes on, but it is not blinking, the head sensor is not working as it is supposed to and should be replaced.

10. When the sensor is on, choose Profile you want to add the sensor to, click on it. Click then the green button next to “Sensors”, and then “Add Sensor” button.

The App has found the sensor when it says on it: “Found 1 sensor”. Click “Continue”.

The App is connected to the sensor when it shows “Connected to 1/1 sensors”. Add Registration code to the line under the text. Click “Continue”. If the App can not find any sensor, switch the sensor off and back on, and try again. If the App finds more than one sensors, switch off all the other sensors than the one you want to register and try again.

11. Choose the sport / discipline the sensor is primarily used for > Click “Continue”

12. Optional: name your sensor and/or just click “Finish”. the App will confirm “Registration is successful”. This means your ACT Head Impact Tracker is ready for action.

In the end of each session of use, make sure to switch off the sensor by pressing on/off-button slowly and firmly twice. Wait for three short led-light blinks to indicate the sensor is switched off. Doing this will prevent impacts from handling and transportation to be recorded to your impact history. Also, it will save energy and prolong your battery lifetime.

See detailed illustrated instructions in User Manual.

– ACT Head Impact Tracker is a measuring device to complement doing safe and responsible sports. It is designed for athletes, coaches, trainers and team personnel, co-athletes, families and friends of athletes.

– ACT Head Impact Tracker head sensor has a built-in automatic switch off in 3 hours after switching it on. If your exercise last longer than 3 hours, remember to switch the sensor back on!

– Head sensor is not suitable for children under 3 years old. Contains small parts. Risk of suffocation!

– Children under 16 years old must use the products and services in adult supervision and must not submit any personal information to ACT Head Impact Tracker products or services.

– ACT Head Impact Tracker needs location services and Bluetooth® wireless connection to be enabled, on and active in the mobile device for ACT Head Impact Tracker smartphone mobile App, and always when using it with ACT Head Impact Tracker head sensor. Otherwise, ACT Head Impact Tracker will not function as intended.

– Mobile device with ACT Head Impact Tracker smartphone mobile App must have valid SIM-card or e-SIM with mobile data and roaming (if needed) enabled, on and active, or be connected to Wi-Fi, to enable data transmission from head sensor to the mobile device with the App, from mobile device to the cloud service and from cloud service to the assigned mobile device(s). Otherwise, ACT Head Impact Tracker will not function as intended.

– Be aware of the data transfer range (Bluetooth® wireless connection reach ) limitations between the head sensor and mobile device with the App. The range may vary for multiple reasons. Indoors and in other compromised conditions, in the case of an incident keep the distance between the two as short as possible. The range can be less than 10 meters.

Please click on the link below to open the user manual (pdf).

Head Sensor User Manual_All languages 17112022.

The App is currently available only in Google Play store and smart phones running Android operating system only. The functionality with all smartphone brands and models has not been tested and cannot be granted. There are brands and models which are not working as intended, or not working at all with ACT Head Impact Tracker. Please ensure to check the list of tested smartphone brands and models purchasing ACT Head Impact Tracker head sensor or accessories. You can find the updating listing in “Before you buy” and “General Information”.

Changes and updates in mobile phone brands, models, operating systems and components, as well as changes and updates made to features, functionalities and user preferences may impact on ACT Head Impact Tracker system and functionality. We are working hard to keep our App updated and functional with as many devices as possible, please help us to do so and tell us on the problems you encounter by emailing us at

To use ACT Head Impact Tracker you need to have User Account. This is how your can create one.

1. Go to Google Play store and download ACT Head Impact Tracker Application to your compatible Android smartphone.
2. Choose “Register” on the opening page > Click “continue”
3. Type in your email address to act as your UserID. Ensure there is no autofillings/autocorrections which should not be there to your email address. Please notice, you can not change your UserID once created. > Click “continue”
4. Create a password with minimum 9 characters to it containing small and capital letters and numbers to it. > Click “continue”
5. Retype your password > Click “continue”.
6. Select the country you live in > Click “continue”
7. Read carefully our “Privacy policy “ > > scroll to the end of the document > Add a tic to the box > Click “ok”
8. Read carefully our “Terms of Service” > scroll to the end of the document > Add a tic to the box > Click “ok”

You have created User Account and can add Profile(s) to it.

To add ACT Head Impact Tracker sensor to your User Account, you have to create Profile. Please notice: you cannot change the information on the Profile, nor remove Profile once created.

1. Click ”Add profile” on App’s landing page.
2. Give name to Profile. For data security reasons, we recommend not to use real or full names on Profiles. > Click “continue”
3. Give a birthday to Profile. For data security reasons we suggest only to use actual birth month and year, which our company needs to fulfill our legal obligations > Click “finish”.
4. Choose your gender > Click “finish”
   You have created Profile to User Account and can add sensor(s) to it.

To add and use ACT Head Impact Tracker sensor, you have to add it to Profile on your User Account. Note: you cannot change Sensor information, nor move or remove Sensor once added to Profile.

1. Click on Profile you wish add sensor to on App’s landing page.
2. Click on green bullet with +-sign on it on “Sensors” block > Click “Add sensor” so that ”Activate the sensor page opens.
3. Insert battery to the sensor, switch it of and back on > Click ”Continue” > Wait for ”Found 1 sensors” text to appear. > Click ”Continue” > Wait for ”Connected to 1/1 sensors” appear > Type the 6-number serial number also acting as registration code to the line > Click ”Continue” If the App can not find any sensor, switch the sensor off and back on, and try again. If the App finds more than one sensors, switch off all the other sensors than the one you want to register and try again.
4. Choose the sport / discipline the sensor is primarily used for > Click “Continue”
5. Optional: name your sensor or just click “Finish”
6. Wait for “Configuring the sensor” to be completed before switching off the sensor or App.
7. Adding sensor is completed and you can switch off the sensor and the App once App confirms “Sensor registered successfully” and you can see it in “Sensors” on Profile.
   You are now all set and good to go. Sport safely!

Due to differences in smartphone brands and models, their operating systems and updates to them, it is recommended to have ACT Head Impact Tracker smartphone mobile App, logged in, open and screen switched on always when using the head sensor(s) and you wish to get the impact information near-real-time.
Unsent impact information will be saved to the sensor and you can retrieve it once the Bluetooth® wireless connection in the mobile phone is available and the mobile device is connected to Wi-Fi our mobile data.

1. The head sensor measures forces on what it is attached to. Hence we strongly recommend attaching ACT Head Impact Tracker head sensor on a head with a tight-fitting head accessory of user’s choosing, also underneath or below a helmet. Head bands specifically designed for the head sensor can be purchased in our webstore (www.act-tracker.com).
   The head sensor can be attached to almost any kind of head accessory or wear with hook and loop -tape, or similar adhesives. Docks specifically designed to accommodate the sensor to narrow sports hairbands can be purchased in our webstore (www.act-tracker.com).
   The back panel of the head sensor has an adhesive surface that you can use by removing the protective film on top of it. We recommend that you use the adhesive surface to attach one piece of hook side of the hook and loop -tape, with which you can attach the head sensor to the ACT Head Impact Tracker headband or other head accessory. Please note that the surface is very adhesive, consider carefully where or what you want to attach to it.
   If you consider attaching head sensor to a helmet, refer to your helmet’s User Manual, Owner’s Guide and website. Your helmet’s warranty might be compromised if you attach anything to it. Always follow the helmet manufacturer’s instructions on safe helmet use. Only use a helmet that meets the applicable safety standard when you use a helmet with the head sensor.
2. Always place the head sensor so that its head side (i.e. the side with the foam, on/off-button and led-light) is towards your head.
3. We recommend placing the head sensor on the back and side of the head, on the more even area after the ear for example. Do not use on the forehead or on the temple for example.
4. Place the head sensor on the area where no direct impacts occur and where it will not get squeezed between your head and the helmet.

CR2032 coin cell battery will last with ACT Head Impact Tracker head sensor versions 1.0 and 1.1 about 8-10 hours of sensor’s on time. In ACT head Impact Tracker head sensor version 1.2. (if purchased the 15th of November or after) the battery lasts something between 100-150 hours of on-time, depending on the battery used.

IMPORTANT NOTE: There is an automatic switch off after 180 minutes of on time in the head sensor to help you to prevent so-called false positive impacts occurring, being recorded and featuring in your impact history from transportation and handling. So, if your exercise last longer than 180 minutes, remember to switch the head sensor back on!