SENSORY EVALUATION AND ITS STATISTICAL-AN ALYSIS ON UNIFORMITY OF GRAIN-STRUCTURE

The uniformity of a microstructure is one of the most important factor s which govern the properties of materials. The evaluation of microstr uctures is generally performed by experts based on sensory tests becau se the uniformity of a microstructure has not been well defined. There fore, it is important to understand how the subjective evaluation is c arried out by experts. The aim of the present paper is to characterize the uniformity evaluation on grain structures, based on the results o btained by the sensory test of 83 panelists for uniformity of 42 grain structures. First, we asked panelists questionnaires about the unifor mity of each grain structure evaluated based on his or her subjectivit y. This is designated as the questionnaire test 1. Next, three items f or the uniformity evaluation were established; i.e. size uniformity, s patial uniformity and a total evaluation which describe the uniformity of grain structures. Then the sensory tests by questionnaires of thes e evaluation items were carried out. This is designated as the questio nnaire test 2. The total evaluation obtained by the questionnaire test 2 was quite similar to that of the questionnaire test 1. Using the re sults obtained by the sensory tests, we analyzed the relationship and/ or interaction between the size uniformity and spatial uniformity as w ell as the influence of the standard length on the uniformity evaluati on.