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13 sensors included in your bracelet or smart watch

Gyroscope, proximity sensor or compass are some of the 13 sensors that your bracelet or smart watch includes. We tell you what they are and their usefulness.

Your bracelet or smart watch can tell you how many steps you have taken, guide you to a specific place, or measure your heart rate, but as it does?

Inside the device there are a series of sensors that are key for its operation, since they are responsible for those interesting tools that you use every day in the smartband or in the smartwatch.

Immerse yourself in the operation of the device that you wear on your wrist by discovering 13 sensors including smart wristbands and watches.

You may already know some of them, such as GPS, but also that some others surprise you. Are you ready to know the sensors that your bracelet or smart watch includes? Let's go there.

Xiaomi Mi Smart Band 3i

Your bracelet or smart watch includes 13 key sensors for its operation.

13 sensors included in your bracelet or smart watch

From the popular Xiaomi Mi Band to the Amazfit GPS watch, wearables dubbed “smart” include a series of sensors that allow their operation.

Some of these sensors are common across all devices, while others are more exclusive and they are included only in some wearables.

Let's see what they are.

Blood oxygen meter, or SpO2

Your bracelet or smart watch may have a blood oxygen meter, known as SpO2 and also included in some Samsung mobiles.

By emitting pulses of light that pass through the skin, this sensor is able to see the color of the blood and analyze how it varies as the heart beats.

This is how your bracelet or smart watch calculates the blood oxygen value, which must be between 95% and 100% to ensure that the cells of your body are receiving all the necessary oxygen.


The gyroscope is the sensor that measures the angular velocity of the device and, thus, its exact position.

Joining the gyroscope data with that of other sensors such as the accelerometer, the bracelet maintains the correct orientation when you move, in addition to being able to differentiate what type of movement you are doing (for example, running instead of walking fast).


Taking a point as a reference, the altimeter recognizes any change in height to which you are.

In this way, the smart watch that you wear on your wrist knows if you are climbing stairs or a mountain, and this is indicated by the calorie count.

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The altimeter recognizes how high you are, for example when you are climbing a slope.


The operation of the Map application would not be possible without the compass, which also helps to tell you how you can get to an exact point without getting lost along the way.


One of the most important sensors on your wearable is the accelerometer, which measures the force of acceleration, direction of acceleration and the gravity and orientation of the device.

As we have mentioned previously, together with the information provided by the gyroscope, it allows the bracelet or watch to know what type of movement you are making.

Proximity sensor

The proximity sensor detects when there are items near the device. So if you get close to your bracelet or smart watch, it will know that you are going to use it and can turn on the home screen.

On the other hand, if you are not using the device, this proximity sensor will make go to sleep to save battery.

Ambient light sensor

The ambient light sensor, also present in mobile phones, takes care of capture the surrounding light level in which it is located and send it to the device to cause certain actions.

If you have activated automatic brightness, this sensor is responsible for measuring the external light to level the brightness of the screen of the bracelet or watch.

Heart rate sensor

Most smartwatches and wristbands have a heart rate sensor that informs you about your beats per minute that your heart gives.

This information is especially useful when you do sports, as it helps you know that your heart rate is correct even if the activity is high.

Bioimpedance sensor

The bioimpedance sensor measures the resistance of your skin to a small amount of electricity emitted by the device's battery electrodes.

Analyzing that resistance to electricity, the bracelet or smart watch can know data such as the water level, breathing rate, or sleep.


Another of the best known sensors of a smart device is the GPS, which is used to locate the exact location of the wearable and track its activity.

This GPS is key to receiving directions from the Map app to reach a destination point.

Android Wear 1.3

GPS helps you orient yourself with your bracelet or smart watch.


The magnetometer on your bracelet or smartwatch measures the Earth's magnetic field and helps you locate where north is.

Together with the GPS, it helps you to know what is your location and where are you looking.

Body temperature sensor

The body temperature sensor, included in some smart wristbands, monitors body temperature throughout the day.

It is a very useful sensor to know if you are going to have a fever or when your menstrual cycle starts.

UV index meter

The last of the sensors on your bracelet or smart watch that we want to talk to you about is the one that measures the intensity of ultraviolet radiation from the Sun.

When you go outside, this sensor manages to detect whether sunlight is dangerous or not and notify you of it through the wearable.

If you have been interested in the operation of all these sensors, but you still do not have a device with these characteristics, you can take a look at our recommendations for best smart watches and best smart bracelets.