First, check the exterior parts of the watch
The appearance of the watch can be checked from the outer shell, crystal, dial and hour, minute and second hands. The case should be free of sand holes and obvious scratches, and the edges and corners should be symmetrical; the screw joint between the back cover and the upper case should be tight; the distance between the two watch rings and the case should be equal, and the hole for installing the ear ring should be at the foot of the case. The center is not deviated, and the depth of the hole is appropriate, so that the watch ring is not easy to fall off.
The watch mirror should be free of flaws and scratches, transparent and bright; the three needles should be installed correctly, and there should be a correct safety gap between the needle and the needle, the mirror and the dial; the dial and the hands should be coated with good finish, no spots, dial scale lines or luminous spots Complete; there is a gap of about 0.1-0.3mm between the handle and the case.
Second, check the sensitivity of the watch
The sensitivity of a watch refers to the flexibility of its balance wheel to swing automatically. The check method is:
(1) Gently shake the watch that has not been wound and has stopped moving, and use the shaking force to observe the movement of the second hand: if the second hand stops moving in a short time, it means that the watch is fully on. After winding, it can be all finished (that is, there is no torque in the mainspring), and the sensitivity is high; if the second hand continues to move for a long time, it means that the watch cannot be completely finished after being wound (that is, the mainspring still stores torque), and the sensitivity is not high Or the meter is malfunctioning.
(2) Turn the head of the watch that has not been wound and stop moving slowly, and observe the start of the second hand: the less the winding of the winder, the earlier the second hand starts, the higher the sensitivity of the watch; otherwise, the lower the sensitivity. Or the meter has other faults. But it should be noted that due to the greater rigidity of the hairspring, the fast-moving watch needs to be wound a little more than the traditional frequency (18000 times/hour) watch machine to start the swing. A watch with high sensitivity will continue to move for a longer time after a full clockwork.
Third, check the spacing and position of the watch hands
There should be a certain distance between the hands of the watch and the watch mirror, the dial, and between the three hands, otherwise they will rub against each other and affect the normal operation of the watch. It can be observed by dialing the needle during inspection. To check whether the position and coordination of the hour and minute hands are normal: set the minute and hour hands to 3 o'clock and 9 o'clock, and observe whether the two hands are at right angles; dial to 6 o'clock, and whether the two hands are in a straight line; dial to 12 o'clock, Whether the two needles overlap.
Fourth, check the watch winding mechanism
Normal watch winding should be easy. When turning the handlebar to wind, it feels looser first, and gradually becomes tighter and tighter. When the handlebar cannot be turned forward, it means that the barrel is fully wound and the winding mechanism is working normally. If there is an abnormal sound of "chattering" or the top teeth slipping when turning the crown to wind, it means that the winding mechanism is malfunctioning.
Five, check the dial mechanism of the watch
The watch should be flexible, reliable and even when the hands are adjusted. The inspection should focus on the tightness of the frictional fit between the minute wheel and the center wheel shaft. When setting the needle, if there is no feeling of looseness or tightness, it means that the friction of the minute wheel is normal and the oil is properly added. On the contrary, the needle setting mechanism is malfunctioning.