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stopwatch are two main types of machinery and electronic, electronic watch and can be divided into two categories, three buttons and four buttons. The vast majority of PE teachers use more is electronic stopwatch, mechanical stopwatch in many places have become history. Electronic stopwatch is a kind of advanced electronic timer, domestic electronic seconds are generally use the oscillation frequency of the quartz oscillator as a time reference, adopt six LCD digital display, display intuitive, easy to read, function more advantages. The author talk about using and maintenance of electronic stopwatch time feel (in four key electronic stopwatch as an example).

1. Record a time: in the case of timer displays, press MODE key to choose, can appear the stopwatch function. Press the START/STOP button to START automatic meter seconds, press the STOP meter seconds again, show the meter data. LAP/RESET button, then the automatic zero.

2. Record multiple time: if you want to record multiple objects at the same time, but don't reach the finish line at the same time, the movement of timing function more ways can be used (the specific number of records to table the instructions). The first press START/STOP the stopwatch conditions, a stopwatch to automatic meter seconds, press the LAP to object to the finish/RESET, the number of seconds to STOP according to different objects, and displayed on the screen above. The stopwatch is still in the record, the internal circuit continues to accumulate meter seconds behind the object. All objects record after the completion of the normal STOP watch, according to the RECALL can check in the previous record, up-and-down available START/STOP and LAP/RESET button.

3. The adjustment of the time, date, time and date of calibration and adjustment if needed, can press MODE key, to display the digital meter seconds, minutes and seconds, hold RECALL button for 2 seconds after see digital flicker can choose adjustment, until shows that need to be adjusted by the correct number of seconds, and then press the RECALL button.

Matters needing attention.

1. Keep the battery change regularly, generally in display dimming can be replaced, don't wait for the electronic stopwatch to replace its battery runs out.

2. The electronic stopwatch placed at ordinary times, safe environment to dry, moisture, shock, anticorrosion, fire prevention, etc.

3. Avoid putting stuff on the electronic stopwatch.

4. Not sure of the situation, don't open to repair, should send professional maintenance.