Increasing the accuracy of measurement for the small-shift, two-channel ultrasonic echolocation-based distance meter

Abstract

Non-contact film thickness meters are most useful to measure physical-mechanical properties of thin polymer-based films. When polymerizing PVC resin at high temperature, the environment becomes very turbulent and is a source for measurement errors. This article explores the measurement errors, which arise when using an echolocation-based distance meter in such environments. Sources of measurement errors are identified and solutions for elimination of these errors are presented. This article provides the solution to avoid the effects of the turbulent environment on measurement accuracy. Additionally, design guidelines for acoustic distance measurement equipment are presented, along with schematic block diagrams. The equipment is designed for maximum measurement accuracy. When acoustic measurements have to be done in a turbulent environment, a version of the electro-acoustic part of the distance meter is presented. It eliminates the negative effects of the turbulent environment on measurement results, therefore very accurate acoustic measurements of small distances become possible.