- Author
- Chang, Y. M. | Grot, R. A.
- Title
- Laboratory Design and Test Procedures for Quantitative Evaluation of Infrared Sensors to Assess Thermal Anomalies.
- Coporate
- National Bureau of Standards, Gaithersburg, MD DCS Corp., Alexandria, VA
- Sponsor
- Department of Energy, Washington, DC
- Report
- NBSIR 85-3131, June 1985,
- Distribution
- Available from National Technical Information Service
- Keywords
- infrared thermal detectors; evaluation; tests; calibrating; temperature; buildings; variability; display devices; infrared radiation; heat loss
- Identifiers
- infrared thermography; modulation transfer functions
- Abstract
- The report presents the description of the laboratory apparatus and preliminary results of the quantitative evaluation of three high-resolution and two low-resolution infrared imaging systems. These systems which are commonly used for building diagnostics are tested under various background temperatures (from -20C to 25C) for their minimum resolvable temperature differences (MRTD) at spatial frequencies from 0.03 to 0.25 cycles per milliradian. The calibration curves of absolute and differential temperature measurements are obtained for three systems. The signal transfer function and line spread function at ambient temperature of another three systems are also measured. Comparisons of the dependence of the MRTD on background temperatures from the measured data with the predicted values given in ASHRAE Standards 101-83 are also included. The dependence of background temperatures for absolute temperature measurements are presented, as well as comparison of measured data and data given by the manufacturer. Horizontal on-axis magnification factors of the geometric transfer function of two systems are also established to calibrate the horizontal axis for the measured line spread function to obtain the modulation transfer function. The variation of the uniformity for horizontal display of these two sensors are also observed. Included are detailed descriptions of laboratory design, equipment setup, and evaluation procedures of each test.