Method and device for increasing the sensitivity of an in-line measurement of the surface cleanliness of steel strips
US11215561B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 10, 2017 |
| Grant date | Jan 4, 2022 |
| Priority date | — |
| Expiry date | Mar 21, 2039 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2021/6484
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method for automated, in-line measurement of a differentiated surface cleanliness, in terms of carbon, of a continuously-moving metal sheet or strip, having a level of surface carbon pollution lower than 100 mg/m2, includes: generating a radiation beam using a source; focusing the radiation beam using a focusing device such that an energy density deposited on the metal strip or sheet is sufficient to create a plasma and generate CN radicals in the plasma if carbon and nitrogen are present; creating a nitrogen atmosphere around the plasma using a sweeping system with a flow rate that prevents any presence of oxygen from air in the plasma; analyzing light emitted by the plasma using an optical collection device, and redirecting the light toward a spectrometer or device for separating wavelengths of the emitted light; measuring an intensity of an intense vibration line of the CN radical.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.