How to distinguish between positive and negative poles of hospital pager power cord

Look at the color distinction. Hospital pager can look at the color to distinguish between positive and negative poles, red is positive, black is negative, this is the national standard provisions. Hospitals, in accordance with laws and regulations and industry norms, for the sick to carry out the necessary medical examination, treatment measures, nursing technology, reception services, rehabilitation equipment, rescue and transportation services, to save lives and help the wounded as the main purpose of medical institutions.