> A Brief Review on Test Systems Using a Ball Probe for Determination of Cooling Characteristics of Quenchants

A wide variety of test systems have been developed to determine cooling characteristics of quenchants. Superior systems for reliability and cost performance are widely used and adopted as domestic and international standards. This review mainly focuses on test systems using a ball probe and discusses their potential. Although ball probes are not defined in current standards, it is known that specific ones used in the past contributed to enhance the test systems in researches. Strengths and limitations inherent in ball probes have been identified from literatures. Prototypes of test systems using a ball probe produced by the author’s group were reviewed briefly, which resolved problems due to a ball probe by using current technologies.