Refractory sight tube for optical temperature measuring device
US5302027A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 22, 1992 |
| Grant date | Apr 12, 1994 |
| Priority date | — |
| Expiry date | Oct 22, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/131
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A sight tube for an optical temperature measuring device suitable for immersion in molten steel comprises an elongated, cylindrical body having an optical sighting bore therein extending axially from an open end of the body to a closed end. The body is a carbon bonded alumina graphite material made from a mix consisting of, in weight percent, between about 5-45% graphite; between about 20-85% alumina; 0 to 15% anti-oxidant; and between about 3-20% phenolic resin binder. The mixture is isostatically pressed in the desired body shape and fired at a temperature in excess of 1400.degree. C. in a reducing atmosphere. The graphite is preferably a high purity flake graphite, greater than 99% pure. The alumina is preferably "brown" fused alumina grain having minimum amounts of volatile elements: sodium (Na), potassium (K), boron (B), phosphorous (P), sulphur (S) and chlorine (Cl). The sodium content, present as Na.sub.2 O in the alumina source is less than 0.05% by weight, and preferably no more than 0.02% by weight.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.