Chai khí chuẩn 15ppm H₂S/ 50ppm CO/ 2.5% CH₄/ 18% O₂/ N₂ Balance - Model 2AL
Chai khí chuẩn 15ppm H₂S/ 50ppm CO/ 2.5% CH₄/ 18% O₂/ N₂ Balance - Model 8AL
