Apparatus and method for calibration in a spectrophotometer
US5691817A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 20, 1996 |
| Grant date | Nov 25, 1997 |
| Priority date | — |
| Expiry date | Aug 20, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01J2003/2866
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A spectrophotometer apparatus (200) is adapted to provide spectral reflectance measurements of object samples. The apparatus (200) comprises a source light (254) and a reflection optics assembly (264, 268). Signals representative of reflected light are analyzed and data provided to an operator representative of the spectral response characteristics of the object sample (252). The apparatus (200) further comprises a side sensor (276) having a fixed spectral response characteristic for compensating the reflectance measurements in accordance with the light intensity emanating from the lamp. For purposes of calibration, a series of time-sequenced measurements are made of a reference sample. Utilizing these measurements, the apparatus (200) provides computations of compensation coefficients for each spectral segment. The compensation coefficients are utilized, with the side sensor measurements, to provide normalization of the reflectance measurements for each segment and for each measurement within the timed sequence. For each segment, a scale factor is then determined. The scale factors, compensation coefficients and side sensor measurements are employed to compensate actual reflectanc…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.