Method for accounting for clamp expansion in a coefficient of thermal expansion measurement
US6672759B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Jul 9, 1998 |
| Grant date | Jan 6, 2004 |
| Priority date | — |
| Expiry date | Nov 10, 2018 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N25/16
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
The present invention is a method to eliminate the influence of clamp dimensional changes on the displacement measurement during the measurement of the coefficient of thermal expansion (CTE) of samples in tension. In a first embodiment clamp dimensional changes can be eliminated by making clamps from a material with near zero CTEs. In another embodiment clamp dimensional changes can be reduced by minimizing the CTE of the clamp material. Finally clamp dimensional changes are taken into account. This is achieved directly by subtracting a prerecorded baseline from the measurements; or by determining the CTE measurement for various sample lengths and obtaining the slope of a straight line through the points on a MD (measured displacement)/DT (temperature range of displacement measurement) versus sample length plot. The slope is the corrected CTE. Clamp dimensional changes can also be taken into account indirectly by obtaining a clamp displacement contribution (CDC) factor which allows to correct measured displacements to result the correct CTE.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.