Chai khí chuẩn 25ppm H₂S/ 100ppm CO/ 2.5% CH₄/ 17% O₂/ N₂ Balance - Model 2AL
Chai khí chuẩn 25ppm H₂S/ 100ppm CO/ 2.5% CH₄/ 17% O₂/ N₂ Balance - Model 8AL
