NPOC calibration standard kit (35 mL each) for combustion based TOC analyzers. Consisting of: preparation water, 0.5, 1.0, 2.5, and 5.0 mg/L C based on KHP, stabilized with HCl Used for drinking water calibration according to installation protocol. Used for multi N/C 2100S, multi N/C 3100 and the duo systems. NPOC calibration standard kit (35 mL each) for combustion based TOC analyzers. Consisting of: preparation water, 0.5, 1.0, 2.5, and 5.0 mg/L C based on KHP, stabilized with HCl Used for drinking water calibration according to installation protocol. Used for multi N/C 2100S, multi N/C 3100 and the duo systems.