One of the biggest attractions we have when buying an Apple Watch is that it not only allows you to see the time, receive notifications and even play, but it also incorporates interesting health features. In this article we will tell you what sensors each Apple Watch has, in addition to explaining what each one consists of.
Sensor types
Each Apple Watch has a multitude of sensors that are used for one thing or another. In addition to a microphone, speaker, processing chips or GPS, we highlight those that serve to perform some type of health measurement or help during sports training. Below we explain what all of them consist of, although making it clear that not all of them are present in each generation, as you will see in the following sections.
Ambient light sensor
This sensor basically allows the watch to keep its screen on or off, in addition to varying the brightness depending on the type of light you have at that time. For the latter, this option must be activated in the settings.
Accelerometer
This is the sensor that receives the movement stimuli. You may have ever wondered how the Apple Watch knows that you are standing, exercising or if you are asleep. Well, precisely this accelerometer is the one who is capable of detecting it.
Gyroscope
Like the previous one, this also helps to detect the movement of our body, knowing at all times if you are standing or not. Thanks to this, the Apple Watch can more accurately detect the movements of any part of the body even if the device itself is on the wrist. It should be noted that in its latest versions it can even detect falls.
Heart rate sensor
In this case we find three versions, the traditional heart rate sensor, the improved one (optical) and the one that also allows for electrocardiograms (electrical). The first two are capable of measuring the beats per minute of the heart and the last one detects electrical activity (Lead I) as long as the app dedicated to it is used and the finger is kept on the digital crown in which it is hosts.
Barometric altimeter
This sensor is capable of detecting the height at which you are, either above sea level or above the ground. Being barometric, it bases its measurements on the relationship between atmospheric pressure and altitude.
Compass
The homonymous application available in some watches is based precisely on the information obtained by this sensor. It is capable of working even without having WiFi or Mobile Data, since its functionality is to be able to say exactly where the north, south, east and west are. Wow, what has been a traditional compass of a lifetime but on a watch.
Blood oxygen sensor
The most recent devices of the brand have this sensor in charge of measuring the level of oxygen we have in the blood. It achieves this through a complex internal analysis mechanism that is performed in seconds after comparing data obtained with a beam of red light that is reflected in the veins.
Apple Watch sensors
Once the different sensors that an Apple watch can incorporate are known, it is necessary to know which of these incorporates each generation. As we have already told you before, not all the sensors mentioned are in all of them, although a good part is.
Apple Watch (original)
- Ambient light sensor.
- Accelerometer.
- Gyroscope.
- Heart rate sensor.
Apple Watch Series 1
- Ambient light sensor.
- Accelerometer.
- Gyroscope.
- Heart rate sensor.
Apple Watch Series 2
- Ambient light sensor.
- Accelerometer.
- Gyroscope.
- Heart rate sensor.
Apple Watch Series 3
- Barometric altimeter.
- Ambient light sensor.
- Accelerometer.
- Gyroscope.
- Optical heart rate sensor.
Apple Watch Series 4
- Barometric altimeter.
- Ambient light sensor.
- Accelerometer (improved compared to Series 3).
- Gyroscope (improved compared to Series 3).
- Optical heart rate sensor.
- Electrical heart rate sensor.
Apple Watch Series 5
- Compass.
- Barometric altimeter.
- Ambient light sensor.
- Accelerometer.
- Gyroscope.
- Optical heart rate sensor (improved compared to Series 4).
- Electrical heart rate sensor.
Apple Watch Series 6
- Compass.
- Barometric altimeter.
- Ambient light sensor.
- Accelerometer.
- Gyroscope.
- Optical heart rate sensor.
- Blood oxygen sensor.
- Electrical heart rate sensor.
Apple Watch SE
- Compass.
- Barometric altimeter.
- Ambient light sensor.
- Accelerometer.
- Gyroscope.
- Optical heart rate sensor.
No, the sensors are not noticeable
If you have never had an Apple Watch, it is very likely that you are wondering if it shows when you take a measurement with any of these sensors, if you notice discomfort and even pain. The answer is blunt: no. The way to proceed with the measurements is completely silent, invisible and painless. Maybe you can see a green or red beam of light depending on the measurement, but having the watch in continuous contact with the wrist is hardly noticeable.
How to know if the sensors are working
In those related to health, just look at the results. If you see that they are strangely anomalous or that they cannot even be carried out accurately, there is a possibility that you do not have the device correctly positioned or you have not followed the instructions for use. However, there is also the possibility that one of these is defective, especially if the watch has suffered a blow.
The way to solve it is by going to Apple’s technical service or, failing that, to an authorized one. There they will be able to verify more exactly what is the origin of the problem. If the failure is due to a problem other than misuse and the device is also under warranty, it is very possible that you will receive a replacement without any additional cost.
There is also the possibility that a software failure prevents the correct operation of any of these sensors, so it is recommended to always have the latest version of watchOS installed. On the other hand, there is also the possibility that certain measurements are not enabled in your territory, such as ECGs.