Microcomputer-controlled Freezing, Data Acquisition and Analysis System for Cold Hardiness Evaluation

Abstract

A computerized system capable of controlling the freezing rate and collecting, storing, and analyzing data from multiple samples to determine their freezing point using low-temperature exotherm analysis is described. Details include electrical diagrams of modifications to the multiplexer/amplifier interface to provide additional signal amplification and permit control of the freezer's compressor. Computer software is described that permits variable temperature decline rates. Data analysis consists of a program in “C” that sequentially compares each data point in a low-temperature exotherm profile. Low-temperature exotherms are identified by a user-specified minimum differential between sequential data points. Examples of exotherm output and data analysis are given.