Hertz Hertz The hertz (symbol: Hz) is the derived unit of frequency in the International System of Units (SI) and is defined as one cycle per second. It is named for Heinrich Rudolf Hertz, the first person to provide conclusive proof of the existence of electromagnetic waves. Hertz are commonly expressed in multiples: kilohertz (10 Hz, kHz), megahertz (10 Hz, MHz), gigahertz (10 Hz, GHz), terahertz (10 Hz, THz), petahertz (10 Hz, PHz), and exahertz (10 Hz, EHz). Some of the unit's most common uses are in the description of sine waves and musical tones, particularly those used in radio- and
Kilogram-force per square centimetre SI units, the unit is converted to the SI derived unit pascal (Pa), which is defined as one newton per square metre (N/m). A newton is equal to a kg·m/s, and a kilogram-force is 9.80665 newtons, meaning that 1 kgf/cm equals 98.0665 kilopascals (kPa). In some older publications, kilogram-force per square centimetre is abbreviated ksc instead of kg/cm. All the Russian origin gauges are indicating pressure in Kgf/cm2 and are calibrated annually. Kilogram-force per square centimetre A kilogram-force per centimetre square (kgf/cm), often just kilogram per square centimetre (kg/cm), or kilopond per centimetre square is a deprecated unit of pressure