(I) Phase error
1. In the phase error the phase difference angle between ∅ & ∅ is kept by using the shading band/ring
2. If the design and location of Shading band/ring is not proper then the phase difference angle between ∅ & ∅ will not be exact , So that, the speed of the aluminum disc may change
3. This type of error is called as a phase angle error
• To minimize the phase error the design quality and location of shading band/ring should be proper
(II) Speed error
Sometimes speed of the disc is more or less than the rated speed due to wrong positioning of braking magnet. Hence meter gives error.
Proper setting up of brake magnet. By changing the position of the brake magnet speed of the rotating disc can be controlled.