astatic coils
Noun: A pair of identical coils connected in parallel but with their windings in opposite directions. This specific arrangement is designed to be insensitive to uniform external magnetic fields, making it useful in sensitive electrical measuring instruments.
This term is highly technical and specific to electrical engineering and physics. It is used when discussing the design of galvanometers, certain types of electrometers, or other instruments that require precise measurement by canceling out the influence of the Earth's magnetic field or other ambient magnetic interference.
- The galvanometer's sensitivity was greatly improved by the use of astatic coils.
- To measure the very weak current, the scientist constructed a system with astatic coils to nullify the background magnetic field.
- The instrument's core component is a pair of astatic coils, which ensures the reading is not affected by its orientation relative to the Earth's magnetic field.
- Astatic Pair: This is a synonymous term often used to describe the same physical arrangement of two coils.
- The principle relies on the coils having zero resultant external magnetic field when a current passes through them. This means their individual magnetic fields cancel each other out externally.
- Conversely, an external magnetic field induces equal but opposite electromotive forces (voltages) in the two coils, which also cancel each other out, resulting in zero electromotive force in the circuit.
- Astatic (adjective): Having no particular orientation or direction; being in unstable equilibrium. In instrumentation, it specifically means designed to be independent of the Earth's magnetic field.
- Example: The needle of an astatic galvanometer is unaffected by the Earth's magnetism.
- Astatic Galvanometer (noun phrase): A sensitive current-detecting instrument that uses astatic coils or an astatic needle system to eliminate the influence of external magnetic fields.
- Coil (noun): A length of something wound in a joined sequence of loops. In electronics, it is a series of loops of wire used to create a magnetic field or to detect a changing magnetic field.
- Astatic pair
This is a compound noun formed from the adjective "astatic" (from Greek a- "not" + statikos "causing to stand") and the noun "coils." Its meaning is entirely specialized to its technical function. There are no common idioms, phrasal verbs, or colloquial uses associated with this term.
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an arrangement of coils used in sensitive electrical instruments; the coils are arranged to give zero resultant external magnetic field when a current passes through them and to have zero electromotive force induced in them by an external magnetic field
