White-light interferometric thickness gauge
Applied Optics
|February 2, 2010
Abstract:
A white-light interferometric thickness gauge has been developed that provides microinch sensitivity to gauge variations in moving transparent films. The new gauge that is suitable for on-line use can be adapted to monitor continuously the thickness profile of transparent films, the thickness of transparent coatings, and the birefringence of optically anisotropic materials. Its performance is relatively insensitive to variations in chemical composition, film temperature, haze level, and measurement geometry.
Related Concept Videos
01:30Electronic Distance Measuring Instruments
Electronic Distance Measuring Instruments (EDMs) are essential tools in modern surveying, offering precise distance measurements by emitting electromagnetic signals and calculating the time required for these signals to travel to a target and return. Two primary types of signals are used in EDMs — light waves and microwaves — each suited to specific environmental and distance requirements. Light-wave-based EDMs utilize either infrared or laser light, providing high accuracy over short distances...
02:46Uncertainty in Measurement: Reading Instruments
Counting is the type of measurement that is free from uncertainty, provided the number of objects being counted does not change during the process. Such measurements result in exact numbers. By counting the eggs in a carton, for instance, one can determine exactly how many eggs are there in the carton. Similarly, the numbers of defined quantities are also exact. For example, 1 foot is exactly 12 inches, 1 inch is exactly 2.54 centimeters, and 1 gram is exactly 0.001 kilograms. Quantities...