Abstract: A method for testing the hermeticity of a sealed cavity within a microelectronic, semiconductor, or other electronic component package includes pressure bombing the package within a detector-fluid bath, attempting thereby to introduce liquid detector fluid into the cavity through any leaks. A detector fluid is used whose vapor state possesses a distinctive physical characteristic that is detectable with known instrumentation. The package is then removed from the bath to permit a quantity of any detector fluid introduced into the cavity to vaporize and evolve for detection. Heating and vibrating the package may be employed to accelerate detector fluid outgassing, together with vacuum withdrawal of the vapor, and detection may employ measurement of infrared absorption. A system for detecting evolving detector fluid vapor includes both a test cell with which to confine the vapor and the instrumentation for measuring infrared absorption of test cell contents.

Abstract: A sulfur monitor analyzer is disclosed and utilizes a burner or flame holder, a burner or reaction chamber, a photomultiplier tube, a light collimator, and chopper blade members with openings so as to permit a flame disposed in the burner or reaction chamber to be seen by the photomultiplier tube at all times. A chemiluminescent radiation mask is disposed operatively between a portion of the chemiluminescent radiation and the photomultiplier tube so as to provide a chopper open mode of operation at which time the photomultiplier tube receives the flame radiation and a fraction of any chemiluminescent radiation surrounding the flames with any remaining fraction of any chemiluminescent radiation being obscured permanently by the chemiluminescent radiation mask. When the chopper is in the closed mode of operation, the photomultiplier tube receives only the radiation from the flame through an aperture defined by an opening in the opaque segment of this chopper or chemiluminescent radiation mask.

Abstract: Sample air is divided into two paths. One path leads through a thermal converter where ambient NO.sub.2 is changed into NO. The other path passes through equivalent tubing to keep the air samples synchronized. Both samples then go to separate cells where each combines with ozone. The resulting chemical reaction produces light, chemiluminescence, which is measured by separate photo-multiplier tubes. Electronic circuits translate the results into simultaneous readings of NO.sub.x and NO concentrations. A difference amplifier subtracts the NO from the NO.sub.x to give a continuous NO.sub.2 value.