Frequency German physicist Heinrich Hertz. One hertz means that an event repeats once per second. If a TV has a refresh rate of 1 hertz the TV's screen will change (or refresh) its picture once a second. A previous name for this unit was cycles per second (cps). The SI unit for period is the second. A traditional unit of measure used with rotating mechanical devices is revolutions per minute, abbreviated r/min or rpm. 60 rpm equals one hertz. As a matter of convenience, longer and slower waves, such as ocean surface waves, tend to be described by wave period rather
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