How Does Kéo Power Bluetooth® Smart System Measure Power and Cadence
The power output measurement of Kéo Power Bluetooth® Smart system is based on strain gauges. Altogether 8 strain gauges are embedded in each pedal axle; each pedal axle has 2 measuring circuits; and each circuit has 4 strain gauges. The force applied to the pedal bends the axle and causes the strain gauges to lengthen or shorten. This leads to a change in the gauge resistance. The force applied to each pedal can be determined by measuring the change in the resistance and the generated power output can be measured when cycling.
The power output measurement is performed simultaneously from both pedals with identical measurement systems. This enables accurate comparison of left and right leg power output. The total power output is the sum of the power outputs of both legs.
Cadence measurement is done with a magnet incorporated into the pedal. For the cadence measurement, there is a reed-relay on the pedal axle and a magnet on the pedal body. With each revolution of the crank, the pedal body does one complete revolution around the pedal axle which generates a pulse to the electronic circuit associated with the reed-relay. By measuring the time interval between these pulses, the cadence can be calculated as rpm (revolutions per minute).