20 yards is equivalent to 20 kilometers per hour, and the speed is about the same as that of people riding bicycles.
Since the unit of speed per hour adopted in China is a metric unit, the correct unit and name of speed in China is kilometer (km)/hour, which is abbreviated as Km/h in English. 1 kilometer (km)=1093.61329834 yards.
The device for measuring speed is called a code meter, which generally consists of the following components:
1. Meter head: It looks like an electronic timer, with a LCD screen, keys, metal contacts, etc. It is the most important part of the code meter.
2. Meter base, wire and sensor: The meter base is usually placed at the horizontal or vertical position of the handlebar of the car to fix the meter head. There is a cable on the watch base of the wired code meter to connect the watch base with the sensor installed on the front fork. The wireless code meter is not connected, and the sensor transmits data to the meter head by transmitting wireless signals.
3. Induction magnet: It is installed on the spokes of the front wheel, and its position is corresponding to the sensor installed on the front fork. The meter head is calculated by the time interval between the induction magnet passing the sensor twice in succession.