Instrument for measurement of vacuum in sealed thin wall packets

Patent · Tue Apr 18 04:00:00 EDT 1995

OSTI ID:46325

Kollie, T G; Thacker, L H; Fine, H A

An instrument is disclosed for the measurement of vacuum within sealed packets, the packets having a wall that it can be deformed by the application of an external dynamic vacuum to an area thereof. The instrument has a detector head for placement against the deformable wall of the packet to apply the vacuum in a controlled manner to accomplish a limited deformation or lift of the wall with this deformation or lift monitored by the application of light as via a bifurcated light pipe. Retro-reflected light through the light pipe is monitored with a photo detector. A change (e.g., a decrease) of retro-reflected light signals the wall movement such that the value of the dynamic vacuum applied through the head be to achieve this initiation of movement is equal to the vacuum within the packet. In a preferred embodiment a vacuum plate is placed beneath the packet to ensure that no deformation occurs on the reverse surface of the packet. A vacuum can be applied to a recess in this vacuum plate, the value of which can be used to calibrate the vacuum transducer in the detector head. 4 figs.

• Research Organization: Lockheed Martin Energy Syst Inc
• DOE Contract Number: AC05-84OR21400
• Assignee: Martin Marietta Energy Systems, Inc., Oak Ridge, TN (United States)
• Patent Number(s): US 5,406,831/A/
• Application Number: PAN: 8-130,261
• OSTI ID: 46325
• Country of Publication: United States
• Language: English

Related Subjects

44 INSTRUMENTATION
INCLUDING NUCLEAR AND PARTICLE DETECTORS
CALIBRATION
DESIGN
MEASURING METHODS
PHOTODETECTORS
VACUUM GAGES
VISIBLE RADIATION