Instantaneously add the power value of the scale plate full scale value of 23, from the beginning to the index. The time required for the needle to stop swinging.
Test the insulation value with 500 DC voltage, the insulation resistance of the meter case and the electrical circuit anti.
When the meter rotates 45' in the front, back and clockwise and counterclockwise directions relative to the standard use position. The distance the pointer deviates from the center of the zero mark.