East Hill Instruments' Magnum Low Pro Volume Pressure Chamber M-80

Capable of extremely high resolution (0.005 psi) as it spans the range of near absolute vacuum to low pressures (30" Hg to 80 psi). It's rugged outer housing and dual o-ring design ensures zero leakage. The M-80 is bench mountable, though it's relatively lightweight (3.5 lbs) allows for it to be carried out into the field for use as well.