A 2-D imaging heat-flux gauge
Abstract
This report describes a new leadless two-dimensional imaging optical heat-flux gauge. The gauge is made by depositing arrays of thermorgraphic-phosphor (TP) spots onto the faces of a polymethylpentene insulator. In the first section of the report, we describe several gauge configurations and their prototype realizations. A satisfactory configuration is an array of right triangles on each face that overlay to form squares when the gauge is viewed normal to the surface. The next section of the report treats the thermal conductivity of TP's. We set up an experiment using a comparative longitudinal heat-flow apparatus to measure the previously unknown thermal conductivity of these materials. The thermal conductivity of one TP, Y2O3:Eu, is 0.0137 W/cm x K over the temperature range from about 300 to 360 K. The theories underlying the time response of TP gauges and the imaging characteristics are discussed in the next section. Then we discuss several laboratory experiments to: (1) demonstrate that the TP heat-flux gauge can be used in imaging applications; (2) obtain a quantum yield that enumerates what typical optical output signal amplitudes can be obtained from TP heat-flux gauges; and (3) determine whether LANL-designed intensified video cameras have sufficient sensitivity to acquire images from the heat-flux gauges. We obtained positive results from all the measurements. Throughout the text, we note limitations, areas where improvements are needed, and where further research is necessary.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- July 1991
- Bibcode:
- 1991STIN...9214332N
- Keywords:
-
- Heat Flux;
- Heat Measurement;
- Imaging Techniques;
- Optical Measuring Instruments;
- Phosphors;
- Thermography;
- Cameras;
- Deposition;
- Heat Transmission;
- Insulators;
- Thermal Conductivity;
- Instrumentation and Photography