frequency
Let an agent handle frequency with its unit, its measurement and its many applications, from radio bands to heart rate, and keep the quantity separate from what is oscillating.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
written by Claude from model knowledge without web access - no source was read, every claim is a lead to verify
Researched by: Claude
Purpose and description
Let an agent handle frequency with its unit, its measurement and its many applications, from radio bands to heart rate, and keep the quantity separate from what is oscillating.
The number of occurrences of a repeating event per unit of time, measured in hertz, where one hertz is one cycle per second.
What it is for: Describing how often something repeats: waves, signals, rotations, heartbeats and events.
It can be measure it, with counters, spectrum analysers or by timing; convert it to period, as the reciprocal; allocate it, for radio spectrum, under regulation; filter or tune to it, in electronics.
Distinguishing features
The reciprocal of period
Distinct from angular frequency, which is 2 pi times frequency
A property of a repeating process, not the process itself
Rates in per-minute units are frequencies too
What it looks like
Not visible directly; shown as a number in hertz, as the spacing of peaks on a trace, or as position on a spectrum display.
Physical character
SI unit: hertz Hz - 1 Hz = 1 per second
audible sound: 20-20000 Hz
mains electricity: 50 or 60 Hz - depends on region
How it is recognised
A value with Hz, kHz, MHz or GHz, or per minute for rates
Peaks on a spectrum plot
Rates such as heart rate and respiratory rate are frequencies in per-minute units
Related models
is a kind of - SI derived quantity
is reciprocal of - f = 1/T
is allocated in - spectrum use is regulated
relates to - for waves, speed equals frequency times wavelength
In practice
Families and kinds
temporal frequency of waves and signals
rotational frequency
physiological rates: heart rate, respiratory rate
radio frequency bands
Identifiers
SI unit symbol Hz hertz
ITU band designation VLF to EHF radio bands
Standards and regulation
SI Brochure
ITU Radio Regulations on spectrum allocation
National spectrum regulators
Failure modes and hazards
Confusing frequency and angular frequency by a factor of 2 pi
Using a frequency without a licence where one is required
Misreading per-minute rates as per-second
Also called
+20
Where this came from
wikidata · CC0 1.0
Also registered as vr.tr.frequency
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 4 bundles · 8 layers · 8 findings · 16 questions.
Quantity and unit What is measured and in what.
The unit and the definition must be explicit to avoid factor errors.
Definition
Cycles per unit time.
Definition used
Ordinary or angular frequency.
- Is this ordinary or angular frequency? definition
- Of what repeating process? definition
Unit
Hertz and multiples, or per minute.
Unit used
The unit and scale.
- In which unit is it given? definition
- How does it convert to hertz? measurement
Measurement How frequency is measured.
Accuracy depends on the reference and the method.
Method
Counting, spectrum, timing.
Method used
The instrument and method.
- How was the frequency measured? provenance
- What reference oscillator or standard was used? provenance
Stability
Drift and jitter.
Stability data
How stable the frequency is.
- How stable is the frequency over time? measurement
- What causes it to drift? definition
Spectrum Radio frequencies and their use.
Radio frequencies are a regulated, shared resource.
Allocation
Bands and services.
Band allocation
The band and allocated service.
- Which band and service does this frequency belong to? definition
- Is a licence required to transmit on it? boundary
Interference
Harmful interference.
Interference risk
Risks of interference.
- What could this transmission interfere with? boundary
- How is interference reported and resolved? action
Applications Where frequency matters.
Frequency appears in medicine, power, audio and communications with different conventions.
Physiological rates
Heart and breathing rates.
Rate context
The rate and its normal range.
- What is this rate, and what is the normal range for this person group? measurement
- When must a clinician interpret it? action
Power and audio
Mains and sound.
Engineering context
The engineering context.
- Which mains frequency applies here? definition
- What frequency range does this audio device handle? measurement
What the second pass must settle
- Should physiological rates be linked to this entry or kept separate?
- How should spectrum allocations be represented per country?
- Should angular frequency be its own entry?