When sourcing calibration cans (often used for gas detection, volume verification, or pressure testing), you must prioritize material integrity and precision. Ensure the cans are made from high-grade aluminum or stainless steel to prevent corrosion and gas absorption. For gas calibration, verify the internal coating (e.g., silica-lined) to ensure the stability of reactive gases. Key metrics include pressure ratings (e.g., 500-1000 psi), water capacity (liters), and valve compatibility (C-10 or CGA connections).