This category contains sites that have information on the theory and practice of testing electronics or electrical equipment. There will also be sites that contains tips, techniques, information, on the practice of measuring electrical and electronics quantities of all descriptions such as capacitance, inductance, frequency, current, power, voltage or resistance. Most vendor sites will be found in Business/Industries/Electronics_and_Electrical/Test_and_Measurement/. These would include sites from companies that sell manufacture, or distribute test equipment that measure the above quantities.