A：The heart rate measurement method of the bracelet is Photoelectric Volume Pulse Waveography (PPG), which is the same principle as the heart rate measurement of Apple Watch.
When the heart contracts, the blood flow at the wrist increases, the green light absorbed by the blood increases, and the reflected green light decreases.
When the heart is dilated, the blood flow at the wrist will be reduced, the green light absorbed by the blood will be reduced, and the reflected green light will increase;
The wristband sensor calculates the heart rate data from the reflected green light frequency.

Precautions:
1. It is forbidden to use an adapter with a charging voltage higher than 5V and a charging current greater than 2A. The charging time is about 90 minutes.
2. It is forbidden to charge in the case of water stains;
3. When measuring heart rate/blood pressure, the heart rate sensor should be close to the skin and well contacted. If the sensor is not tightly exposed, the measured value will be inaccurate;
4. The smart bracelet is an electronic monitoring product, not for medical reference, the data is for reference only;
5, photoelectric sensors are highly sensitive components, be careful of hard objects. Wear it for a period of time, there may be sweat and dust, and it can be cleaned regularly with a soft cloth.

About N+1
N+1 Smart Watch Company is a professional smart bracelet manufacturer, who supports OEM/ODM orders, has got nearly ten years of export experience, we've got hundreds of private models in the field of smart bracelets, sports bracelets, and Bluetooth watches;

The products are mainly exported to European and American markets;

Our products are rich in styles, such as smart watches, Bluetooth call watches,  SIM card call watches, Women's exclusive smart bracelets, outdoor climbing watches, etc., all of them support OEM/ODM orders ;

In the field of health monitoring, our smart watches have powerful functions, such as body temperature monitoring, blood pressure monitoring, blood oxygen detection, ECG detection, sleep monitoring, etc.;

In the field of sports monitoring, our smart watch is your best sports companion. It has got outdoor sports watches, waterproof functions, step counting & distance & calories, GPS motion motion track , and special sports functions such as air pressure, altitude, SOS call, etc. ；

There are also exquisite bracelets specially designed for women, with women's menstrual period reminder function;

According to the quality needs of different customers, we have silicone straps, steel straps and Milanese straps for your option; There are also click screentouch, full circle / square screentouch, square screentouch, racket screentouch options on the watch dial display;