| 摘要 |
A cermet resistance material for firing on to an electrically non-conductive base such as glass to form a resistance layer having a low temperature coefficient of resistivity, comprises a finely-divided mixture containing 50 to 95% by weight of glass and 5 to 50% by weight of an alloy of ruthenium and rhodium, the alloy preferably containing at least 10% by weight ruthenium. The resistance material is made by mixing the resinates of the metals with finely-divided glass particles, heating the mixture to remove volatile and organic material and to decompose the metal compounds, and so produce a dry material consisting of very small glass particles coated with or mixed with extremely small particles of metal alloy. Resistance elements are made by mixing the dry material with a suitable liquid carrier such as 7% ethylhydroxyethyl cellulose, 93% octyl alcohol and applying the fluid composition to the base material by methods such as silk screening, stencilling or spraying, a coating of approximately 0.001 inch giving a resistivity of 30-10,000 ohms per square. Any glass composition may be used in the resistance material and several examples of such compositions are given. |
