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Title: Instrument for measurement of vacuum in sealed thin wall packets

Patent ·
OSTI ID:5352777

An instrument is described for the measurement of vacuum within sealed packets, the packets having a wall sufficiently thin that it can be deformed by the application of an external vacuum to small 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. An abrupt change (e.g., a decrease) of retro-reflected light signals the wall movement such that the value of the vacuum applied through the head to achieve this initiation of movement is equal to the vacuum within the packet. In a preferred embodiment a vacuum reference plate is placed beneath the packet to ensure that no deformation occurs on the reverse surface of the packet. A packet production line model is also described. 3 figures.

DOE Contract Number:
AC05-84OR21400
Assignee:
PTO; EDB-94-047019
Patent Number(s):
US 5249454; A
Application Number:
PPN: US 7-826799
OSTI ID:
5352777
Resource Relation:
Patent File Date: 27 Jan 1992
Country of Publication:
United States
Language:
English