Dear Users, 

Due to scheduled network maintenance, the official website will be temporarily unavailable during the following period: • 

Maintenance Period: September 2 to September 3, 2025 • 

Service Restoration: September 4, 2025 (normal operation will resume)  

For urgent communications or inquiries during this period, please contact us via email at: nil@analysis.org.cn.
We apologize for any inconvenience caused and appreciate your understanding and patience.

Yours sincerely,

China NIL Research Center for Proficiency Testing
September 1, 2025