A laser scanning system for frost height measurements

This paper presents a new non-contact method for measuring frost height on heat exchanger fins. Previously used methods only allow one or two measurements per minute and are thus only practical for smooth frosted surfaces with height variations in only one direction. The new method uses a laser and two light sensors to collect transmitted and reflected laser light from a frosted surface. A three-dimensional representation may be obtained by scanning several vertical sections at different locations on each heat exchanger fin that is coated with frost. Preliminary data is presented showing the distribution of frost height on a fin using the transmitted and reflected sensor signals.