Normal frequency
A standard frequency (or calibration frequency ) is a highly accurate frequency derived from a frequency standard .
Normal frequency over radio stations
The normal frequency is often identical to the carrier frequency of time signal services and radio transmitters in the long and medium wave range. Since 1991, the FBAS signal of the ZDF's analog television stations has also been used for distribution in the Federal Republic of Germany .
In the shortwave range , numerous time signals and normal frequency transmitters transmit on the standard frequencies 2,500 kHz, 5,000 kHz, 10,000 kHz and 15,000 kHz.
List of standard frequencies
- MSF Anthorn , Great Britain (60 kHz, time signal transmitter)
-
HBG Prangins , Switzerland (75 kHz, time signal transmitter)(out of service since January 2012) - DCF77 Mainflingen , Germany (77.5 kHz, time signal transmitter)
-
Deutschlandfunk Donebach , Germany (153 kHz, broadcast station)(out of service since January 2015) - France Inter Allouis , France (162 kHz, radio station)
- BBC Radio 4 Droitwich , UK (198 kHz, broadcast)
- Polskie Radio 1 Solec Kujawski , Poland (225 kHz, radio station)
- RAI Radiouno , Milano , Italy (900 kHz, radio station)
Standard frequency in acoustics
Acoustically, a sinusoidal frequency of 1000 Hz is called the normal rate, it is considered here as a center frequency . The units phon and sone for volume are derived from it and it is the starting point for standard frequencies according to EN ISO 266. It is used as a measurement tone and distributed as a standard frequency, for example (especially earlier) with test images at certain times or by telephone from the Austrian Federal Office for calibration and surveying .
The normal frequency, which is important for musical instruments, the normal pitch or concert pitch of 440 Hz , is also distributed via the latter .