Negative ventilation provides many advantages:
• Small leaks around the openings in the cage lid have a minimal effect upon respiratory gas
concentrations because the intended fresh air is drawn from the immediate atmosphere around the
cage. A fan inside the cage ensures that all the gases are uniformly mixed.
• The sample line used in a positive ventilation system is eliminated as the air supply line ventilates the
cage and supplies the gas sample to the Gas Sensor chain.
The following sub-sections detail the components used in the Negative Ventilation Setup.