the material of the hydrophobic element 132 may be any manner of oleophobic or hydrophobic material referred to hereinafter only as hydrophobic for simplicity the material of the hydrophobic element 132 may include mflono u00ae ptfe membrane versapor u00ae r membrane supor u00ae r membrane all available from pall specialty materials etc the hydrophobic material allows air to vent but is repellant to fluids the hydrophobic material allows air to pass until the material becomes wetted wetting is a saturation of the pores of the hydrophobic material if wetting occurs further air cannot pass through the material the mechanical air eliminator 150 in the embodiment shown includes a deformable conduit 152 that fits into a port 172 in the drip chamber 102 a deformable ball 166 is positioned in the conduit 152 and normally substantially blocks and seals the conduit 152 when the conduit 152 and the ball 166 are manually deformed or squeezed by a force f air 112 is allowed to pass around the ball 166 and through the conduit 152 when the deforming force f is removed the ball 166 resumes its normal shape and the mechanical venting ceases the automatic air eliminator 120 and the mechanical air eliminator 150 may be attached to any three port drip chamber as shown alternatively the mechanical air eliminator 150 and the automatic air eliminator 120 may be combined into a single device not shown sharing a common conduit and fitting into an available port of a two port drip chamber in operation air 112 may substantially automatically and continuously vent through the automatic air eliminator 120 by passing through the hydrophobic element 132 the automatic air eliminator 120 therefore substantially automatically and continuously vents air and does so.