Accurist 6W50 Operating Instructions Manual page 40

3. Press BR Button to set the chronograph 1/20th second hand to the 0 position.
The chronograph hands can be advanced rapidly by continuously pressing the
top or bottom right buttons.
4. Once the hands have been zeroed, reset the time and return the crown to
Position A.
5. Press BR Button to check that the chronograph hands are reset to the 0
position.