ammonia clock: meaning, definition, pronunciation and examples
Very LowTechnical/Scientific/Historical
Quick answer
What does “ammonia clock” mean?
A highly precise timekeeping device, an atomic clock that uses the vibrational frequency of ammonia molecules (specifically the nitrogen atom) as its timebase.
Audio
Pronunciation
Definition
Meaning and Definition
A highly precise timekeeping device, an atomic clock that uses the vibrational frequency of ammonia molecules (specifically the nitrogen atom) as its timebase.
Historically significant as one of the first types of atomic clocks, developed in the late 1940s, providing revolutionary accuracy compared to quartz clocks. The term now often refers to this specific historical technology rather than contemporary atomic clocks.
Dialectal Variation
British vs American Usage
Differences
No significant lexical differences. Usage is identical in technical contexts.
Connotations
Associated with the pioneering era of atomic timekeeping; implies an older, less precise technology compared to modern atomic clocks.
Frequency
Extremely rare in both dialects, confined to historical or specialised physics/engineering texts.
Grammar
How to Use “ammonia clock” in a Sentence
The [ammonia clock] [verb: provided/operated/functioned] as a frequency standard.[Noun: Scientists/Engineers] developed the [ammonia clock].Vocabulary
Collocations
Examples
Examples of “ammonia clock” in a Sentence
verb
British English
- The prototype was designed to ammonia-clock its way to greater precision.
- They attempted to ammonia-clock the satellite's timer.
American English
- The lab sought to ammonia-clock the network's synchronization.
adverb
British English
- The signal was generated ammonia-clock precisely.
American English
- The system ran ammonia-clock accurate for its time.
adjective
British English
- The ammonia-clock era predated the caesium standard.
- He was an expert in ammonia-clock technology.
American English
- The ammonia-clock mechanism was prone to drift.
Usage
Meaning in Context
Business
Virtually never used.
Academic
Used in historical or technical discussions of timekeeping and frequency standards.
Everyday
Not used.
Technical
Precise term for a specific type of atomic clock based on ammonia molecule inversion.
Vocabulary
Synonyms of “ammonia clock”
Strong
Neutral
Weak
Vocabulary
Antonyms of “ammonia clock”
Watch out
Common Mistakes When Using “ammonia clock”
- Confusing it with all modern atomic clocks. Using it as a general synonym for 'atomic clock'. Mispronouncing 'ammonia' with stress on the second syllable (/æˈmoʊniə/).
FAQ
Frequently Asked Questions
No, it is obsolete. Modern primary time standards use caesium or rubidium atoms, and hydrogen masers, which offer far greater stability and accuracy.
The principle was proposed by Isidor Rabi, and the first working ammonia clock (or ammonia maser) was built by Harold Lyons and his team at the U.S. National Bureau of Standards in 1949.
Early ammonia clocks had an accuracy of about one part in 10^8 (losing/gaining about a second per year), which was revolutionary at the time but is vastly inferior to modern caesium clocks (accurate to one part in 10^16).
Ammonia molecules (NH3) have a strong, well-defined microwave absorption line at around 23.87 GHz due to the quantum mechanical 'inversion' of the nitrogen atom through the plane of the hydrogen atoms, making it detectable with 1940s technology.
A highly precise timekeeping device, an atomic clock that uses the vibrational frequency of ammonia molecules (specifically the nitrogen atom) as its timebase.
Ammonia clock is usually technical/scientific/historical in register.
Ammonia clock: in British English it is pronounced /əˈməʊniə ˈklɒk/, and in American English it is pronounced /əˈmoʊniə ˈklɑːk/. Tap the audio buttons above to hear it.
Phrases
Idioms & Phrases
- “[No common idioms]”
Learning
Memory Aids
Mnemonic
Imagine a clock face with the chemical structure of ammonia (NH3) in the centre, its nitrogen atom ticking back and forth like a pendulum.
Conceptual Metaphor
PRECISION IS MOLECULAR VIBRATION (The regular vibration of a molecule is conceptualised as the 'ticking' of a clock).
Practice
Quiz
What is the primary timekeeping element in an ammonia clock?