LEEI-25 is a delicately designed intelligent system for RF electron spin resonance. The system can be used to observe the phenomenon of electron spin resonance, determine the g-factor of DPPH, and precisely measure the parameters of the geomagnetic field where the system is located, such as the geomagnetic vertical component, geomagnetic horizontal component, and magnetic dip.

As a reliable system, LEEI-25 employs a built-in microprocessor to automatically determine resonant point and acquire measurement data with high precision. The system can be configured in manual or automatic mode, and therefore it is suitable for experimental education at colleges and universities.