GASTEC Hydrogen Sulfide Data Logger, Model GHS-8AT-EX, continuously measures and logs H2S gas concentrations in sewage facilities. GASTEC Calibration Kit CK-11E series enable users to easily perform on-site span calibration for the gas sensor. GASTEC also provides economical, easy-to-use, highly accurate, and very reliable environmental safety devices that can detect and measure hazardous gases and vapors on the spot, up to 350 different types.