I didn't see the gold ring washed in the gold shop, but I heard a sneer. What machine was it washed with?

Now the gold shop uses an ultrasonic cleaning machine, and the cold laughter is the sound that the machine makes when it works.

Ultrasonic cleaning machine operation?

1; Pour water and cleaning agent into the ultrasonic cleaning machine, and do not overflow the warning water level line.

2; Put in the gold and silver jewelry you want to clean.

3; Press the power button to start cleaning and adjust the time level.

After being cleaned by ultrasonic cleaning machine, the jewelry is as bright as when it was just bought.

(1) What is a vocational qualification certificate?