System and process for detecting properties of travelling sheets in the machine direction
US4947684A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Jan 27, 1989 |
| Grant date | Aug 14, 1990 |
| Priority date | — |
| Expiry date | Jan 27, 2009 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N33/346
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
To determine machine-direction variations in measurements of a travelling sheet during production, the sheet is repeatedly traversed with a scanning sensor and, during each traverse, measurements are taken at a plurality of locations. Then, a series of reference slice locations are selected which extend in the true cross-direction. For the reference locations, measurement values are estimated based upon actual measurements. Then, for each scan, the average of the estimated measurement values is calculated. Next, cross-directional variations in values at each slice location along selected scans are calculated by subtracting the average value from the estimated value at each location along the scan. During the next consecutive scans, machine-directional variations in the sheet property at slice locations are calculated by determining the difference between the measured value and the calculated cross-directional variation value for that slice location along the prior scan.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.