But its potential to kill workers in or near confined spaces should never be underestimated. On Nov. 5, 2005, two contractors working at Valero Energy Corp.'s Delaware City, Del., oil refinery died from nitrogen asphyxiation.
The hertz (symbol Hz) is the 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.ach musical note corresponds to a particular frequency which can be measured in hertz. An infant's ear is able to perceive frequencies ranging from 20 Hz to 20,000 Hz; the average adult human can hear sounds between 20 Hz and 16,000 Hz.
Gigahertz, generally abbreviated GHz, refers to frequencies in the billions of cycles per second range. Giga is the standard multiplier for 1 billion, and Hertz is the standard unit for measuring frequencies, expressed as cycles or occurrences per second. One GHz is equivalent to 1,000 megahertz (MHz).