Fully Automatic Trace Moisture Analyzer Measures Gas Moisture Content

The moisture content of gas samples is generally low, and common measurement methods cannot meet the accuracy requirements for such samples. The Karl Fischer coulometric method can measure down toPPMlevel, making it an excellent method for determining gas moisture content.

The fully automatic model is based on the Karl Fischer coulometric principle, with a minimum measurement as low as2micrograms of water, making it very suitable for measuring gas moisture content. Special attention is needed for such samples; it is best to use a separate, balanced electrolytic cell equipped with a gas injection needle at the inlet or a direct gas injection line.  

General procedure:

      Introduce the gas directly into the electrolytic cell via the gas injection needle at the inlet or a direct gas injection line. The needle or line should be inserted as deep as possible below the surface of the Karl Fischer reagent. Install a flow meter on the gas line and adjust the flow rate with a control valve. The flow rate ranges from50mL/minto250ml/min (3…15L/h).

The gas line should be thoroughly flushed with the sample(10…30min)to achieve a stable equilibrium. A three-way valve can be installed so that during the flushing process, the sample does not pass through the electrolytic cell.

    For different types of gas samples, additional equipment such as gas samplers or sampling cylinders, various connector fittings, electronic balances, timers, hoses, etc., may be required.

Examples of such samples that have been tested include: butane, natural gas, Freon, carbon dioxide, methane, propane, oxygen, nitrogen, etc.