Stoelting has configured an open circuit system
(without absorption chamber or breathing bag) for scientists
who work only with rodents and small animals.
The tidal volumes of small (<7kg) animals do not allow for an
absorption chamber and recycling. A slow flow of gas from the
vaporizer output is released at the animal’s nose.
Anesthetic gas from a vaporizer is connected via tubing to the
scavenger unit and passed to a mask covering the animals nostrils.
Gases are removed from the mask and the immediate vicinity by
vacuum in an outer mask.