Design and operation of an apparatus for calorimetric emittance measurements of pipe surfaces
Abstract
A technique for the measurement of the total hemispherical emittance of pipe surfaces is described, and design and operational details are given. The technique is conceptually simple. A long test pipe (e.g., 3.4 m) is mounted concentrically inside a Pyrex glass pipe. The system is evacuated, and the test pipe is heated by means of an electrical resistance heater. By varying the electrical power level, one can measure the test pipe emittance as a function of temperature. By using a simple correction to account for the finite length of the test pipe, one can calculate the results using the simple expression for infinite, concentric cylinders. Results agree with measurements by reflectance techniques and have a nominal relative error of less than 10%.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 October 1981
 Bibcode:
 1981STIN...8233676R
 Keywords:

 Calorimeters;
 Heat Measurement;
 Pipes (Tubes);
 Cylindrical Bodies;
 Glass;
 Structural Design;
 Surface Temperature;
 Temperature Dependence;
 Vacuum Apparatus;
 Fluid Mechanics and Heat Transfer