1. Appearance inspection: observe the consistency of markings on the dial, back cover and handle, and check the case, surface and needle for serious scratches.
2. Sensitivity test: In the state of complete relaxation of the clocks, up and down, down and down, if the second hand walking sensitivity is considered qualified, otherwise it is insensitive.
3. Sound check: When winding, the machine core can not have "click" sound. If there is a sound or slip, it indicates that there is a problem with the up-regulation part of the machine. In addition, if the interval between the "beep" sounds of the audiometer is obviously different in length, it indicates that the meter has serious deviation.
4. Pull the needle check: When the needle is pulled counterclockwise, the second needle can stop or retreat, but when the needle is stopped, the second needle should start moving again. Otherwise, it means that the inner part of the machine core is not tightened properly.
5. coincidence check: Put the clockwise, minute and second hand to the overlapping position, check whether there is friction between the second hand and glass, the clockwise and dial, and the three needles. Then the observation was made at 3, 6, 9 and 12 points.
6. Calendar checking: When checking watches with weekly and calendar display functions, there should be no phenomenon of half-word or no-word skipping.
7. According to the national standard, according to the timing accuracy, the domestic watches are divided into four grades. The diurnal differences of the first, second, third and fourth grades are greater or less than +30 seconds, +-45 seconds, +-60 seconds, +-90 seconds, respectively.