Structural design of Sangli CTP-II split magnetic balance: $r $n adopts stainless steel material, separating the circuit control part, magnetic field measurement part, and magnetic field generation part. This split design can reduce interference and facilitate maintenance. The $r $n base is adjustable, making it easy to adjust the magnetic field level and ensure measurement accuracy. It also has a built-in cold light power supply, providing sufficient and soft light for experimental operations, making it easy to observe. $r $n magnetic field system: The $r $n magnet is a Guglie type, single yoke, with a magnetic column diameter of 40mm and an adjustable magnetic gap width of 0-40mm, which can be flexibly adjusted according to experimental needs.