1. DC constant current source: 
Output current: 50A (with stability better than ±2% during the test process and ensuring display accuracy) 
Output voltage: 60V 
Accessories: Cables and alligator clips. 
2. Spruce board: Size: > 2.6m×1.5m Thickness: 0.75in (approximately 19.05mm). 
3. Single layer rice paper: 
Unit area weight: 12~30g/m2 
4. Coarse cotton yarn: Unit mass area: 26~28m2/kg Count: 32×28/inch.