The ZSS uses a non-dispersive infrared absorbance system which is made up by an infrared semiconductor laser for a light source and a photo-diode for the photo-detection. Measure NH3, HCl, H2O, O2, CO, CO2, and CH4 gas concentrations in a stack at high speed.Excellent Stability for Long PeriodsMaintenance Free & Highly EfficientOperates in High Temperatures & Dusty ConditionsFast Response (2 sec. or less)Low Interference with Other GasesZero Drift: (+-) 2.0% FSHigh Vibration Resistance