Metrology is the science of measurement and its application. It may include both experimental and theoretical determinations in any field of science and technology. Broadly, the metrology is categorized into scientific, legal, or industrial metrology depending upon the type of application and level of accuracy and precision of the carried out measurement. In Chap. 3, details of some of the common microwave measurement were given, out of which automation of test measurement of attenuation is explained in Chap. 4. The proposed LabVIEW application can measure the attenuation of the DUT. The expression of the measurement results along with the evaluated uncertainty is explained in this chapter.