Как правильно пишется мгц

ГГц

генри-герц

————————

гигагерц

Словарь сокращений русского языка .
2014.

Смотреть что такое «ГГц» в других словарях:

• ГГЦ — Гипрогазцентр ДОАО «Гипрогазцентр» ОАО «Газпром» г. Нижний Новгород, организация ГГЦ городской гериатрический центр Санкт Петербург Источник: http://www.microsoft.com/Rus/Casestudies/CaseStudy.aspx?id=85 ГГц генри герц …   Словарь сокращений и аббревиатур

• ГГц — …   Википедия

• Ггц — …   Википедия

• ГГц — генри герц …   Русский орфографический словарь

• Проверка коэффициента отражения ПЭВ в полосе частот от 0,4 — 37,5 ГГц — 4.5. Проверка коэффициента отражения ПЭВ в полосе частот от 0,4 37,5 ГГц 4.5.1. Для проведения испытаний применяют аппаратуру и оборудование со следующими техническими характеристиками: генератор сигналов* с: полосой частот 0,4 37,5 ГГц,… …   Словарь-справочник терминов нормативно-технической документации

• Проверка коэффициента отражения ПЭВ в полосе частот от 0,03 до 0,4 ГГц включительно — 4.4. Проверка коэффициента отражения ПЭВ в полосе частот от 0,03 до 0,4 ГГц включительно 4.4.1. Для проведения измерений применяют аппаратуру и оборудование со следующими техническими характеристиками: генератор сигналов с: полосой частот 0,03… …   Словарь-справочник терминов нормативно-технической документации

• ОСТ 45.193-2002: Фиксированная и радиовещательная спутниковые службы. Станции земные, работающие в полосах частот: 27,5-31,0 ГГц на передачу, 17,7-21,2 ГГц и 10,7-12,75 ГГц на прием. Технические требования. Методы испытаний — Терминология ОСТ 45.193 2002: Фиксированная и радиовещательная спутниковые службы. Станции земные, работающие в полосах частот: 27,5 31,0 ГГц на передачу, 17,7 21,2 ГГц и 10,7 12,75 ГГц на прием. Технические требования. Методы испытаний: Внешнее… …   Словарь-справочник терминов нормативно-технической документации

• ГОСТ Р 8.617-2006: Государственная система обеспечения единства измерений. Государственная поверочная схема для средств измерений мощности электромагнитных колебаний в диапазоне частот от 37,50 до 53,57 ГГц — Терминология ГОСТ Р 8.617 2006: Государственная система обеспечения единства измерений. Государственная поверочная схема для средств измерений мощности электромагнитных колебаний в диапазоне частот от 37,50 до 53,57 ГГц оригинал документа:… …   Словарь-справочник терминов нормативно-технической документации

• ГОСТ Р 52459.3-2009: Совместимость технических средств электромагнитная. Технические средства радиосвязи. Часть 3. Частные требования к устройствам малого радиуса действия, работающим на частотах от 9 кГц до 40 ГГц — Терминология ГОСТ Р 52459.3 2009: Совместимость технических средств электромагнитная. Технические средства радиосвязи. Часть 3. Частные требования к устройствам малого радиуса действия, работающим на частотах от 9 кГц до 40 ГГц оригинал документа …   Словарь-справочник терминов нормативно-технической документации

• ГОСТ Р 52459.19-2009: Совместимость технических средств электромагнитная. Технические средства радиосвязи. Часть 19. Частные требования к подвижным земным приемным станциям спутниковой службы, работающим в системе передачи данных в диапазоне 1,5 ГГц — Терминология ГОСТ Р 52459.19 2009: Совместимость технических средств электромагнитная. Технические средства радиосвязи. Часть 19. Частные требования к подвижным земным приемным станциям спутниковой службы, работающим в системе передачи данных в… …   Словарь-справочник терминов нормативно-технической документации

From Wikipedia, the free encyclopedia

hertz
Top to bottom: Lights flashing at frequencies f = 0.5 Hz, 1.0 Hz and 2.0 Hz; that is, at 0.5, 1.0 and 2.0 flashes per second, respectively. The time between each flash – the period T – is given by 1⁄f (the reciprocal of f ); that is, 2, 1 and 0.5 seconds, respectively.
General information
Unit system	SI
Unit of	frequency
Symbol	Hz
Named after	Heinrich Hertz
In SI base units	s−1

The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second.^[1][3] The hertz is an SI derived unit whose expression in terms of SI base units is s⁻¹, meaning that one hertz is the reciprocal of one second.^[2] It is named after Heinrich Rudolf Hertz (1857–1894), the first person to provide conclusive proof of the existence of electromagnetic waves. Hertz are commonly expressed in multiples: kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz).

Some of the unit’s most common uses are in the description of periodic waveforms and musical tones, particularly those used in radio- and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. The units are sometimes also used as a representation of the energy of a photon, via the Planck relation E = hν, where E is the photon’s energy, ν is its frequency, and h is the Planck constant.

Definition[edit]

The hertz is equivalent to one cycle per second. The International Committee for Weights and Measures defined the second as «the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom»^[4][5] and then adds: «It follows that the hyperfine splitting in the ground state of the caesium 133 atom is exactly 9192631770 hertz, ν_{hfs Cs} = 9192631770 Hz.» The dimension of the unit hertz is 1/time (T⁻¹). Expressed in base SI units, the unit is the reciprocal second (1/s).

In English, «hertz» is also used as the plural form.^[6] As an SI unit, Hz can be prefixed; commonly used multiples are kHz (kilohertz, 10³ Hz), MHz (megahertz, 10⁶ Hz), GHz (gigahertz, 10⁹ Hz) and THz (terahertz, 10¹² Hz). One hertz simply means «one event per second» (where the event being counted may be a complete cycle); 100 Hz means «one hundred events per second», and so on. The unit may be applied to any periodic event—for example, a clock might be said to tick at 1 Hz, or a human heart might be said to beat at 1.2 Hz.

The occurrence rate of aperiodic or stochastic events is expressed in reciprocal second or inverse second (1/s or s⁻¹) in general or, in the specific case of radioactivity, in becquerels.^[7] Whereas 1 Hz is one cycle (or periodic event) per second, 1 Bq is one radionuclide event per second on average.

Even though frequency, angular velocity, angular frequency and radioactivity all have the dimension T⁻¹, of these only frequency is expressed using the unit hertz.^[8] Thus a disc rotating at 60 revolutions per minute (rpm) is said to have an angular velocity of 2π rad/s and a frequency of rotation of 1 Hz. The correspondence between a frequency f with the unit hertz and an angular velocity ω with the unit radians per second is

and

The hertz is named after Heinrich Hertz. As with every SI unit named for a person, its symbol starts with an upper case letter (Hz), but when written in full it follows the rules for capitalisation of a common noun; i.e., «hertz» becomes capitalised at the beginning of a sentence and in titles, but is otherwise in lower case.

History[edit]

The hertz is named after the German physicist Heinrich Hertz (1857–1894), who made important scientific contributions to the study of electromagnetism. The name was established by the International Electrotechnical Commission (IEC) in 1935.^[9] It was adopted by the General Conference on Weights and Measures (CGPM) (Conférence générale des poids et mesures) in 1960, replacing the previous name for the unit, «cycles per second» (cps), along with its related multiples, primarily «kilocycles per second» (kc/s) and «megacycles per second» (Mc/s), and occasionally «kilomegacycles per second» (kMc/s). The term «cycles per second» was largely replaced by «hertz» by the 1970s.^{[10][failed verification]}

In some usage, the «per second» was omitted, so that «megacycles» (Mc) was used as an abbreviation of «megacycles per second» (that is, megahertz (MHz)).^[11]

Applications[edit]

Sound and vibration[edit]

Sound is a traveling longitudinal wave, which is an oscillation of pressure. Humans perceive the frequency of a sound as its pitch. Each musical note corresponds to a particular frequency. An infant’s ear is able to perceive frequencies ranging from 20 Hz to 20000 Hz; the average adult human can hear sounds between 20 Hz and 16000 Hz.^[12] The range of ultrasound, infrasound and other physical vibrations such as molecular and atomic vibrations extends from a few femtohertz^[13] into the terahertz range^[14] and beyond.^[15]

Electromagnetic radiation[edit]

Electromagnetic radiation is often described by its frequency—the number of oscillations of the perpendicular electric and magnetic fields per second—expressed in hertz.

Radio frequency radiation is usually measured in kilohertz (kHz), megahertz (MHz), or gigahertz (GHz). Light is electromagnetic radiation that is even higher in frequency, and has frequencies in the range of tens (infrared) to thousands (ultraviolet) of terahertz. Electromagnetic radiation with frequencies in the low terahertz range (intermediate between those of the highest normally usable radio frequencies and long-wave infrared light) is often called terahertz radiation. Even higher frequencies exist, such as that of gamma rays, which can be measured in exahertz (EHz). (For historical reasons, the frequencies of light and higher frequency electromagnetic radiation are more commonly specified in terms of their wavelengths or photon energies: for a more detailed treatment of this and the above frequency ranges, see Electromagnetic spectrum.)

Computers[edit]

Further information on why the frequency, including for gigahertz (GHz) etc., is a flawed speed indicator for computers: Megahertz myth

In computers, most central processing units (CPU) are labeled in terms of their clock rate expressed in megahertz (MHz) or gigahertz (GHz). This specification refers to the frequency of the CPU’s master clock signal. This signal is nominally a square wave, which is an electrical voltage that switches between low and high logic levels at regular intervals. As the hertz has become the primary unit of measurement accepted by the general populace to determine the performance of a CPU, many experts have criticized this approach, which they claim is an easily manipulable benchmark. Some processors use multiple clock cycles to perform a single operation, while others can perform multiple operations in a single cycle.^[16] For personal computers, CPU clock speeds have ranged from approximately 1 MHz in the late 1970s (Atari, Commodore, Apple computers) to up to 6 GHz in IBM Power microprocessors.

Various computer buses, such as the front-side bus connecting the CPU and northbridge, also operate at various frequencies in the megahertz range.

SI multiples[edit]

SI multiples of hertz (Hz)

Higher frequencies than the International System of Units provides prefixes for are believed to occur naturally in the frequencies of the quantum-mechanical vibrations of massive particles, although these are not directly observable and must be inferred through other phenomena. By convention, these are typically not expressed in hertz, but in terms of the equivalent energy, which is proportional to the frequency by the factor of the Planck constant.

Unicode[edit]

The CJK Compatibility block in Unicode contains characters for common SI units for frequency. These are intended for compatibility with East Asian character encodings, and not for use in new documents (which would be expected to use Latin letters, e.g. «MHz»).^[17]

• U+3390 ㎐ SQUARE HZ
• U+3391 ㎑ SQUARE KHZ
• U+3392 ㎒ SQUARE MHZ
• U+3393 ㎓ SQUARE GHZ
• U+3394 ㎔ SQUARE THZ

See also[edit]

• Alternating current
• Bandwidth (signal processing)
• Electronic tuner
• FLOPS
• Frequency changer
• Normalized frequency (signal processing)
• Orders of magnitude (frequency)
• Periodic function
• Radian per second
• Rate
• Sampling rate

Notes and references[edit]

External links[edit]

• SI Brochure: Unit of time (second)
• National Research Council of Canada: Cesium fountain clock
• National Research Council of Canada: Optical frequency standard based on a single trapped ion (archived 23 December 2013)
• National Research Council of Canada: Optical frequency comb (archived 27 June 2013)
• National Physical Laboratory: Time and frequency Optical atomic clocks
• Online Tone Generator

From Wikipedia, the free encyclopedia

hertz
Top to bottom: Lights flashing at frequencies f = 0.5 Hz, 1.0 Hz and 2.0 Hz; that is, at 0.5, 1.0 and 2.0 flashes per second, respectively. The time between each flash – the period T – is given by 1⁄f (the reciprocal of f ); that is, 2, 1 and 0.5 seconds, respectively.
General information
Unit system	SI
Unit of	frequency
Symbol	Hz
Named after	Heinrich Hertz
In SI base units	s−1

The hertz (symbol: Hz) is the unit of frequency in the International System of Units (SI), equivalent to one event (or cycle) per second.^[1][3] The hertz is an SI derived unit whose expression in terms of SI base units is s⁻¹, meaning that one hertz is the reciprocal of one second.^[2] It is named after Heinrich Rudolf Hertz (1857–1894), the first person to provide conclusive proof of the existence of electromagnetic waves. Hertz are commonly expressed in multiples: kilohertz (kHz), megahertz (MHz), gigahertz (GHz), terahertz (THz).

Some of the unit’s most common uses are in the description of periodic waveforms and musical tones, particularly those used in radio- and audio-related applications. It is also used to describe the clock speeds at which computers and other electronics are driven. The units are sometimes also used as a representation of the energy of a photon, via the Planck relation E = hν, where E is the photon’s energy, ν is its frequency, and h is the Planck constant.

Definition[edit]

The hertz is equivalent to one cycle per second. The International Committee for Weights and Measures defined the second as «the duration of 9192631770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium-133 atom»^[4][5] and then adds: «It follows that the hyperfine splitting in the ground state of the caesium 133 atom is exactly 9192631770 hertz, ν_{hfs Cs} = 9192631770 Hz.» The dimension of the unit hertz is 1/time (T⁻¹). Expressed in base SI units, the unit is the reciprocal second (1/s).

In English, «hertz» is also used as the plural form.^[6] As an SI unit, Hz can be prefixed; commonly used multiples are kHz (kilohertz, 10³ Hz), MHz (megahertz, 10⁶ Hz), GHz (gigahertz, 10⁹ Hz) and THz (terahertz, 10¹² Hz). One hertz simply means «one event per second» (where the event being counted may be a complete cycle); 100 Hz means «one hundred events per second», and so on. The unit may be applied to any periodic event—for example, a clock might be said to tick at 1 Hz, or a human heart might be said to beat at 1.2 Hz.

The occurrence rate of aperiodic or stochastic events is expressed in reciprocal second or inverse second (1/s or s⁻¹) in general or, in the specific case of radioactivity, in becquerels.^[7] Whereas 1 Hz is one cycle (or periodic event) per second, 1 Bq is one radionuclide event per second on average.

Even though frequency, angular velocity, angular frequency and radioactivity all have the dimension T⁻¹, of these only frequency is expressed using the unit hertz.^[8] Thus a disc rotating at 60 revolutions per minute (rpm) is said to have an angular velocity of 2π rad/s and a frequency of rotation of 1 Hz. The correspondence between a frequency f with the unit hertz and an angular velocity ω with the unit radians per second is

and

The hertz is named after Heinrich Hertz. As with every SI unit named for a person, its symbol starts with an upper case letter (Hz), but when written in full it follows the rules for capitalisation of a common noun; i.e., «hertz» becomes capitalised at the beginning of a sentence and in titles, but is otherwise in lower case.

History[edit]

The hertz is named after the German physicist Heinrich Hertz (1857–1894), who made important scientific contributions to the study of electromagnetism. The name was established by the International Electrotechnical Commission (IEC) in 1935.^[9] It was adopted by the General Conference on Weights and Measures (CGPM) (Conférence générale des poids et mesures) in 1960, replacing the previous name for the unit, «cycles per second» (cps), along with its related multiples, primarily «kilocycles per second» (kc/s) and «megacycles per second» (Mc/s), and occasionally «kilomegacycles per second» (kMc/s). The term «cycles per second» was largely replaced by «hertz» by the 1970s.^{[10][failed verification]}

In some usage, the «per second» was omitted, so that «megacycles» (Mc) was used as an abbreviation of «megacycles per second» (that is, megahertz (MHz)).^[11]

Applications[edit]

Sound and vibration[edit]

Sound is a traveling longitudinal wave, which is an oscillation of pressure. Humans perceive the frequency of a sound as its pitch. Each musical note corresponds to a particular frequency. An infant’s ear is able to perceive frequencies ranging from 20 Hz to 20000 Hz; the average adult human can hear sounds between 20 Hz and 16000 Hz.^[12] The range of ultrasound, infrasound and other physical vibrations such as molecular and atomic vibrations extends from a few femtohertz^[13] into the terahertz range^[14] and beyond.^[15]

Electromagnetic radiation[edit]

Electromagnetic radiation is often described by its frequency—the number of oscillations of the perpendicular electric and magnetic fields per second—expressed in hertz.

Radio frequency radiation is usually measured in kilohertz (kHz), megahertz (MHz), or gigahertz (GHz). Light is electromagnetic radiation that is even higher in frequency, and has frequencies in the range of tens (infrared) to thousands (ultraviolet) of terahertz. Electromagnetic radiation with frequencies in the low terahertz range (intermediate between those of the highest normally usable radio frequencies and long-wave infrared light) is often called terahertz radiation. Even higher frequencies exist, such as that of gamma rays, which can be measured in exahertz (EHz). (For historical reasons, the frequencies of light and higher frequency electromagnetic radiation are more commonly specified in terms of their wavelengths or photon energies: for a more detailed treatment of this and the above frequency ranges, see Electromagnetic spectrum.)

Computers[edit]

Further information on why the frequency, including for gigahertz (GHz) etc., is a flawed speed indicator for computers: Megahertz myth

In computers, most central processing units (CPU) are labeled in terms of their clock rate expressed in megahertz (MHz) or gigahertz (GHz). This specification refers to the frequency of the CPU’s master clock signal. This signal is nominally a square wave, which is an electrical voltage that switches between low and high logic levels at regular intervals. As the hertz has become the primary unit of measurement accepted by the general populace to determine the performance of a CPU, many experts have criticized this approach, which they claim is an easily manipulable benchmark. Some processors use multiple clock cycles to perform a single operation, while others can perform multiple operations in a single cycle.^[16] For personal computers, CPU clock speeds have ranged from approximately 1 MHz in the late 1970s (Atari, Commodore, Apple computers) to up to 6 GHz in IBM Power microprocessors.

Various computer buses, such as the front-side bus connecting the CPU and northbridge, also operate at various frequencies in the megahertz range.

SI multiples[edit]

SI multiples of hertz (Hz)

Higher frequencies than the International System of Units provides prefixes for are believed to occur naturally in the frequencies of the quantum-mechanical vibrations of massive particles, although these are not directly observable and must be inferred through other phenomena. By convention, these are typically not expressed in hertz, but in terms of the equivalent energy, which is proportional to the frequency by the factor of the Planck constant.

Unicode[edit]

The CJK Compatibility block in Unicode contains characters for common SI units for frequency. These are intended for compatibility with East Asian character encodings, and not for use in new documents (which would be expected to use Latin letters, e.g. «MHz»).^[17]

• U+3390 ㎐ SQUARE HZ
• U+3391 ㎑ SQUARE KHZ
• U+3392 ㎒ SQUARE MHZ
• U+3393 ㎓ SQUARE GHZ
• U+3394 ㎔ SQUARE THZ

See also[edit]

• Alternating current
• Bandwidth (signal processing)
• Electronic tuner
• FLOPS
• Frequency changer
• Normalized frequency (signal processing)
• Orders of magnitude (frequency)
• Periodic function
• Radian per second
• Rate
• Sampling rate

Notes and references[edit]

External links[edit]

• SI Brochure: Unit of time (second)
• National Research Council of Canada: Cesium fountain clock
• National Research Council of Canada: Optical frequency standard based on a single trapped ion (archived 23 December 2013)
• National Research Council of Canada: Optical frequency comb (archived 27 June 2013)
• National Physical Laboratory: Time and frequency Optical atomic clocks
• Online Tone Generator

Герц (русское обозначение: Гц, международное обозначение: Hz) — единица частоты периодических процессов (например, колебаний) в Международной системе единиц (СИ) а также в системах единиц СГС и МКГСС^[1]. Герц — производная единица, имеющая специальные наименование и обозначение. Через основные единицы СИ герц выражается следующим образом:

1 Гц = 1 с⁻¹.

1 Гц означает одно исполнение (реализацию) такого процесса за одну секунду, другими словами — одно колебание в секунду, 10 Гц — десять исполнений такого процесса, или десять колебаний за одну секунду.

В соответствии с общими правилами СИ, касающимися производных единиц, названных по имени учёных, наименование единицы герц пишется со строчной буквы, а её обозначение — с заглавной.

История

Единица названа в честь немецкого учёного-физика XIX века Генриха Герца, который внёс важный вклад в развитие электродинамики. Название было учреждено Международной электротехнической комиссией (МЭК) в 1930 году^[2]. В 1960 году XI Генеральной конференцией по мерам и весам вместе с учреждением СИ это название было принято для единицы частоты в СИ.

Кратные и дольные единицы

Десятичные кратные и дольные единицы образуют с помощью стандартных приставок СИ.

Герц и беккерель

Кроме герца в СИ существует ещё одна производная единица, равная секунде в минус первой степени (1/с): таким же соотношением с секундой связан беккерель. Существование двух равных, но имеющих различные названия единиц, связано с различием сфер их применения: герц используется только для периодических процессов, а беккерель — только для случайных процессов распада радионуклидов^[3]. Хотя использовать обратные секунды в обоих случаях было бы формально правильно, рекомендуется использовать единицы с различными названиями, поскольку различие названий единиц подчёркивает различие природы соответствующих физических величин.

Примеры

• Диапазон частот звуковых колебаний, которые способен слышать человек, лежит в пределах от 20 Гц до 20 кГц.
• Сердце человека в спокойном состоянии бьётся с частотой приблизительно 1 Гц (Примечательно, что Herz в переводе с немецкого означает «сердце». Однако фамилия великого физика пишется Hertz).
• Частота ноты ля первой октавы по стандарту настройки, принятому в настоящее время, составляет 440 Гц. Является стандартной частотой камертона (нота ля первой октавы является эталонной для настройки музыкальных инструментов). В концертных залах применяется настройка в 442 Гц, иногда выше.
• Частоты колебаний электромагнитного поля, воспринимаемого человеком как видимое излучение (свет), лежат в диапазоне от 3,9·10¹⁴ до 7,9·10¹⁴ Гц.
• Частота электромагнитного излучения, используемого в микроволновых печах для нагрева продуктов, обычно равна 2,45 ГГц.

См. также

• Беккерель

Примечания

Русский[править]

ГГц

• Графическое сокращение названия единицы измерения гигагерц. ◆ Частота 10 ГГц была выделена для связи.

Белорусский[править]

ГГц

• Графическое сокращение названия единицы измерения гігагерц. ◆ Частата 10 ГГц была выдзелена для сувязі.

Украинский[править]

ГГц

• Графическое сокращение названия единицы измерения гігагерц. ◆ Частота 10 ГГц була виділена для зв’язку.

Категории:

• Русский язык
• Графические сокращения названий единиц измерения/ru
• Слова из 3 букв/ru
• Белорусский язык
• Графические сокращения названий единиц измерения/be
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