What is the Bluetooth transmission range of Polar H9/H10 HR sensor?
The transmission range with H9/H10 is 5 meters (16.4 ft) at the minimum in optimal conditions. Typically the range varies between 10 to 35 meters (32.8 to 114.8 ft), and in extremely rare top outdoors conditions, on an open field, the range can reach even up to 100 meters (328.1 ft). There are several variables that affect the range and therefore an exact range cannot be stated. The best range is achieved with line-of-sight positioning between the sensor and receiver. Indoors, obstacles such as concrete walls will attenuate the radio signal when passing through and the effective range will be drastically reduced, but on the other hand the radio signal can bounce from walls and thereby improve the range inside the room in cases where there is no direct line-of-sight situation between the sensor and receiver (for example, in a sports hall or gym).
Some other variables affecting the range are signals from other wireless devices (such as Wi-Fi stations or a large number of other Bluetooth devices nearby; even a microwave oven can interfere with the Bluetooth signal) and the quality of the receiver. Polar receivers are confirmed to meet the requirements. High air humidity can also affect the range in some cases. Furthermore, a human body creates considerably high attenuation for the Bluetooth radio signal and therefore, if you hold your receiver behind your back near your skin, the connection might be lost (for example, while speed skating)
