Abstract: A manual apparatus for testing the vacuum of an evacuated vial. A cylindrical test enclosure having an access opening in the wall thereof is provided for the vial. A rotatable sleeve surrounds the enclosure and has a like access opening in registration with and rotatable to be in alignment with the access opening of the test enclosure. When the two access openings are rotated out of alignment, high voltage radio frequency power is applied to the exterior of the vial, and an intense flash of light occurs next to the vial to cause ionization of gas within the vial. The ionization current which results is indicative of the value of the vacuum within the vial.