Gas sampling bags are used with the gas analyzer to perform gas calibration for metabolism applications performed with WBP or Inhalation Tower systems.  

The multi-layer foil bags for gas sampling provided with the DSI system are chemically inert and have very good stability for low molecular weight compounds such as CO, CO2, and permanent gases. The bags have a 4-layer barrier that minimizes the gas permeability and are equipped with a screw cap combo valve with a hose connection to fit a 3/16” ID tubing.

• Fluoropolymer tubing is recommended. Vinyl and Silicone tubing are not recommended due to leachability. 
• Shortly before use, it is recommended, to flush the gas sampling bags with Ultra-Pure Nitrogen, or Zero Air.
• Do not exceed 2 to 3 PSI maximum (or flow rate 3L/min) when filling the gas sampling bags. These bags are designed to inflate sufficiently to contain gas samples - NOT TO BE PRESSURIZED.
• Only fill the bag to 75-80% of the maximum capacity (3/4). Do not fill the bag to the point where it is taut.
• After connecting the gas sampling bags to the Auxiliary Controller, leave them connected with valves off when not in use. The valves of the bags should stay open only during the gas calibration procedure when gas from the sampling bags is used.
• The gas sampling bags should be refilled when the gas volume is less than 100cc or after 30 days. The multi-layer foil bags can conservatively retain original O2 and CO2 concentrations for at least 30 days. After that refilling of the bags should be considered.
• Always use clean tubing for connecting the gas bags and handle the valves of the gas sampling bags carefully, to prevent gas contamination.

Operating instructions for the screw cap combo valve are attached.