The pneumotach holds two sets of screens: one set for the animal chamber, and one for the reference chamber.  The screens will slowly collect debris as they are used which will increase the resistance to airflow in and out of the chamber. If the screens become too resistive, FinePointe will be unable to calibrate the chamber and prompt the user to replace the screens.

Under normal conditions, only screens on the animal chamber side of the pneumotach need to be replace, as the screens on the reference chamber collect less debris. This is because air flow to the reference chamber is minimal.

The number of screens on each side of the WBP pneumotach per species chamber is noted below:

• Mouse Pup
  • Animal chamber 4
  • Reference chamber 4
• Mouse – Adult
  • Animal chamber 2
  • Reference chamber 8
• Rat / Guinea Pig / Rabbit
  • Animal chamber 3
  • Reference chamber 10