SEMI-CONDUCTORS FOR HIGH TEMPERATURE THERMOMETRY.
Abstract
To provide feasibility proof of semi-conductor techniques for surface temperature measurements in the 1000 - 2500 K range a materials analysis was conducted which resulted in the choice of ZrO2 plus 15 mol % Y2O3 composition for the sensor, Ir plus 40 wt. % Rh for lead wires and BeO for the insulator. Factors influencing the electrical properties of refractory oxides were reviewed and a c resistance measurements were made on sensor materials to temperatures as high as 1400 K. Fabrication techniques investigations included hot pressing, slip casting, and melting. Fabricated bead type thermistors were tested in air and vacuo up to 2500 K for periods up to 20 hours. Thermistor properties (electrical resistance, thermal shock resistance, voltage characteristics, and stability) compared favorably with base thermocouple functions. The complete measurement system was designed for a voltage output, linearized measurement circuit and a time-lag compensation circuit. An estimation of response characteristics and an error analysis of the entire system was made. Applications, including direct immersion in high velocity gases and surface measurements of high-and-low conductivity materials, are discussed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1966
- Accession Number
- AD0480105
Entities
People
- Ernest G. Wolff
- Fred M. Viles