Comparison of Measurements of Internal Temperatures in Ablation Material by Various Thermocouple Configurations
Abstract
The internal temperatures measured by various thermocouple configurations in a charring ablator and in a porous ceramic subjected to severe heating in an electric-powered arc jet are presented and discussed. The results show that measurement errors of several hundred degrees can result from the conduction of heat from the hot junction of the thermocouple by the thermocouple lead wires. The measurement of internal temperatures in materials with low values of thermal conductivity subjected to severe heating by thermocouples requires that the thermocouple produce a minimum temperature disturbance within the material. A comparison was made of several thermocouple sensors designed to minimize internal temperature disturbances caused by heat conduction from the hot junction by the sensor material. These thermocouple sensors had short lengths of the sensor lead wire in the isothermal plane of the hot junction. This comparison showed that the temperatures indicated by these thermocouple sensors agreed reasonably well.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 01, 1964
- Accession Number
- ADA396284
Entities
People
- Marvin B. Dow
Organizations
- National Aeronautics and Space Administration