Infrared Transmission Measurements through Screening Smokes: Experimental Considerations,
Abstract
In order to evaluate the effect of tactical screening smokes on infrared transmission, it is necessary to understand the complex interactions among many variables. The transmission depends upon the bulk properties of the material (e.g., index of refraction), as well as the particle-size distribution, concentration, and pathlength. The measured or apparent transmission can be quite different from the true transmission because several simple basic facts are often overlooked. Therefore, it becomes quite difficult to compare data from different laboratories or from field tests because the experimental methodology is different at each location. In principle, it is possible to calculate the transmission of the smoke if the particle-size distribution, concentration, pathlength, and the complex index of refraction are known. But these parameters are not always known precisely, and one resorts to experimentation to define them. The experiment becomes that of introducing a smoke with unknown infrared properties between the target and the detector. The ratio of the signal received with smoke to that without smoke is taken as the transmission.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1980
- Accession Number
- ADA090404
Entities
People
- Gerald C. Holst
Organizations
- United States Army Armament Research, Development and Engineering Center