What is the difference between the 220V production test and the 120V production test?

The difference is that the power supply voltage and the calibration load are different, and the two production tests are formulated for sockets of different voltages. Which voltage measurement is used depends on the firmware and the rated voltage of the socket design. If the socket usage scenario is 220V, 220V production test is recommended. If the usage scenario is 120V, it is recommended to use 120V production test.