Hertz (unit)

hertz
hertz
	Hz, Hz
Value	frequency
System	SI
Type of	derivative

Hertz (Russian designation: Hz , international designation: Hz ) is a unit of frequency of periodic processes (for example, oscillations ) in the International System of Units (SI) and also in the systems of units of the GHS and the ICSS ^[1] . Hertz is a derivative unit having a special name and designation. Through the basic units of SI, hertz is expressed as follows:

1 Hz = 1 s ⁻¹ .

1 Hz means one execution (implementation) of such a process in one second , in other words - one oscillation per second, 10 Hz - ten executions of such a process, or ten oscillations in one second.

In accordance with the general SI rules regarding derivative units named after scientists, the name of the hertz unit is written with a lowercase letter , and its designation with a capital letter .

Blink with a frequency f = 0.5 Hz (Hz = Hertz), 1.0 Hz and 2.0 Hz, where

x

{\ displaystyle x}

x

Hz means

x

{\ displaystyle x}

x

flashes per second. T-interval and T =

y

{\ displaystyle y}

y

c (c = second) means that

y

{\ displaystyle y}

y

the number of seconds after which one flash appears. Frequency and Interval are always inversely proportional: f = 1 / T; T = 1 / f.

Content

1 History
2 Multiples and submultiples
3 Hertz and Becquerel
4 Unicode characters
5 Examples
6 See also
7 notes

History

The unit is named after a German scientist , a 19th-century physicist Heinrich Hertz , who made an important contribution to the development of electrodynamics . The name was established by the International Electrotechnical Commission (IEC) in 1930 ^[2] . In 1960, the XI General Conference on Weights and Measures together with the establishment of SI, this name was adopted for the unit of frequency in SI.

Multiple and fractional units

Decimal multiple and fractional units are formed using standard SI prefixes .

Multiple				Equity
value	title	designation		value	title	designation
10 ¹ Hz	decahertz	dahz	daHz	10 ⁻¹ Hz	decihertz	dhz	dHz
10 ² Hz	hectohertz	ghz	hHz	10 ⁻² Hz	centihertz	sz	cHz
10 ³ Hz	kHz	kHz	kHz	10 ⁻³ Hz	millihertz	MHz	mHz
10 ⁶ Hz	megahertz	MHz	MHz	10 ⁻⁶ Hz	microhertz	mhz	µHz
10 ⁹ Hz	gigahertz	GHz	Ghz	10 ⁻⁹ Hz	nanohertz	nHz	nHz
10 ¹² Hz	terahertz	THz	Thz	10 ⁻¹² Hz	picohertz	pHz	pHz
10 ¹⁵ Hz	petahertz	Pz	PHz	10 ⁻¹⁵ Hz	femtohertz	fhz	fHz
10 ¹⁸ Hz	exahertz	Ehz	Ehz	10 ⁻¹⁸ Hz	attohertz	aHz	aHz
10 ²¹ Hz	zettahertz	Zhz	Zhz	10 ⁻²¹ Hz	zeptohertz	zhz	zHz
10 ²⁴ Hz	iottahertz	Ihz	Yhz	10 ⁻²⁴ Hz	ioctohertz	Hz	yHz
not recommended not applied or rarely applied in practice

Hertz and Becquerel

In addition to hertz, in SI there is another derivative unit equal to a second in minus the first degree (1 / s): becquerel is connected in the same ratio to a second. The existence of two equal, but with different unit names, is associated with the difference in the scope of their application: hertz is used only for periodic processes, and becquerel is used only for random decay processes of radionuclides ^[3] . Although using reverse seconds in both cases would be formally correct, it is recommended to use units with different names, since the difference in unit names emphasizes the difference in the nature of the corresponding physical quantities .

Unicode characters

Unicode notation. ^[four]
Symbol	Title	Unicode number
㎐	Hertz (Square HZ)	U + 3390
㎑	Kilohertz (Square KHZ)	U + 3391
㎒	Megahertz (Square MHZ)	U + 3392
㎓	GHz (Square GHZ)	U + 3393
㎔	Terahertz (Square THZ)	U + 3394

Examples

The frequency range of sound vibrations that a person is able to hear lies in the range from 20 Hz to 20 kHz.
A person ’s heart beats in a calm state with a frequency of approximately 1 Hz (It is noteworthy that Herz in German means “heart.” However, the name of the great physicist is written by Hertz).
The note frequency for the first octave according to the tuning standard currently adopted is 440 Hz. It is the standard tuning fork frequency (the note for the first octave is the reference for tuning musical instruments). In concert halls, a setting of 442 Hz is applied, sometimes higher.
The oscillation frequencies of the electromagnetic field , perceived by man as visible radiation ( light ), lie in the range from 3.9 × 10 ¹⁴ to 7.9 × 10 ¹⁴ Hz.
The frequency of electromagnetic radiation used in microwave ovens to heat products is usually 2.45 GHz.

Notes

↑ Dengub V.M. , Smirnov V.G. Units of quantities. Dictionary dictionary. - M .: Publishing house of standards, 1990. - S. 35. - 240 p. - ISBN 5-7050-0118-5 .
↑ History of the IEC (English) . IEC Date of treatment September 1, 2013.
↑ Table 3. Coherent derived units in the SI with special names and symbols on the website of the International Bureau of Weights and Measures
↑ Unicode Consortium. The Unicode Standard 12.0 - CJK Compatibility ❰ Range: 3300–33FF ❱ ( unspecified ) . Unicode.org (2019). Circulation date May 24, 2019.

[1] Dengub V.M. , Smirnov V.G. Units of quantities. Dictionary dictionary. - M .: Publishing house of standards, 1990. - S. 35. - 240 p. - ISBN 5-7050-0118-5 .

[2] History of the IEC (English) . IEC Date of treatment September 1, 2013.

[3] Table 3. Coherent derived units in the SI with special names and symbols on the website of the International Bureau of Weights and Measures

[Unicode-U3300-4] Unicode Consortium. The Unicode Standard 12.0 - CJK Compatibility ❰ Range: 3300–33FF ❱ ( unspecified ) . Unicode.org (2019). Circulation date May 24, 2019.