A measured voltage of 220V does not necessarily mean the system is operating stably. When the multimeter display and actual equipment behavior begin to contradict each other, the inspection should be expanded to include load conditions, electrical contact quality, and waveform characteristics rather than repeatedly performing the same voltage measurement.

What is ASTM Type I, II, and III distilled water? Learn about the differences in purity, conductivity, resistivity, and applications of each grade of water used in laboratories, testing, research, and production.

What is the HRC hardness of heat-treated steel? Learn about the hardness of S45C, SCM440, and SKD11, how to evaluate HRC measurement rsults, and the reasons why steel may achieve incorrect hardness after heat treatment.

Rockwell, Brinell, and Vickers are three of the most common hardness testing methods currently used. Learn about the differences in measurement principles, application ranges, and how to choose the right method for each type of material.

HRC, HRB, and HRA all belong to the Rockwell hardness system but are applied to different material groups. Understanding the differences between HRC, HRB, and HRA helps in selecting the correct testing method, accurately reading specifications, and avoiding unnecessary errors in material quality assessment.