Method and apparatus for high resolution analysis
US5368391A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 18, 1992 |
| Grant date | Nov 29, 1994 |
| Priority date | — |
| Expiry date | Nov 18, 2012 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N25/4833
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention relates to analytical methods for determining the composition of a material that undergoes a transition as a function of a driving variable. As applied to thermogravimetric analysis (TGA), a first preferred embodiment comprises (1) decreasing the heating rate when deviations from a baseline signal are detected; (2) establishing a minimum heating rate; (3) forcing the heating rate to a predetermined maximum whenever the rate of change of the weight change with respect to the temperature falls below a predetermined value; and (4) adjusting the heating rate according to the rate of change of the weight of the sample to track a predetermined rate of change of the weight of the sample. A second preferred embodiment comprises (1) selecting either a high-productivity or a high-resolution mode; (2) in both modes, controlling the rate of temperature increase according to a function containing an exponential term, wherein the argument of the exponential term includes the percent weight change per unit time of the sample; (3) in the high-productivity mode, choosing the function so that when the percentage weight change per minute of the sample is small, the heating rate …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.