Use the “Quick Search” box to locate your required term and/or definition. The following “Search conditions” can be used to refine your search: “Contains”, “Begins with”, “Ends with”, “Equals”, “Does not contain” or “Does not equal.”
Eng ID Term Definition
3061
magnetometer: cesium
An OPTICAL PUMPING MAGNETOMETER which employs a cesium absorption cell.
3062
magnetometer: flux-gate
An instrument which uses a wire wound saturable core inductor to measure the EARTH'S MAGNETIC FIELD.
3063
magnetometer: helium
An OPTICAL PUMPING MAGNETOMETER which employs a helium absorption cell.
3064
magnetometer: nuclear precession
A MAGNETOMETER that utilizes the precessional characteristics of hydrogen nuclei when in an ambient MAGNETIC FIELD. Also known as proton pr... more
A MAGNETOMETER that utilizes the precessional characteristics of hydrogen nuclei when in an ambient MAGNETIC FIELD. Also known as proton precession mag­netometer.
3065
magnetometer: optical pumping
A highly sensitive MAG­NETOMETER which employs a metastable helium or alkali metal absorption cell whose ATOMS absorb maximum energy from an... more
A highly sensitive MAG­NETOMETER which employs a metastable helium or alkali metal absorption cell whose ATOMS absorb maximum energy from an infrared BEAM when a frequency modula­tion oscil­lator is tuned to its resonant FREQUENCY. The resonant FREQUENCY is proportional to the strength of the EARTH'S MAGNETIC FIELD.
3066
magnetometer: proton precession
See MAGNETOMETER: NUCLEAR PRECESSION.
3067
magnetometer: quartz horizontal
A MAGNETOMETER in which the torque exerted on a suspended MAGNET by the EAR­TH's horizontal MAGNETIC FIELD is balanced against the torque e... more
A MAGNETOMETER in which the torque exerted on a suspended MAGNET by the EAR­TH's horizontal MAGNETIC FIELD is balanced against the torque exerted by the quartz suspension fibre when twisted through 360°.
3068
magnetometer: rubidium vapour
An OPTICAL PUMPING MAG­NETOMETER which employs a rubidium vapour absorption cell.
3069
magnetometer: transit
An instrument used primarily for observing the declination of the EARTH'S MAGNETIC FIELD.
3070
magnetometer: unifilar
A MAGNETOMETER, designed for use on SHORE, employed to measure the horizontal intensity of the EARTH's MAGNETISM; it can also be used to det... more
A MAGNETOMETER, designed for use on SHORE, employed to measure the horizontal intensity of the EARTH's MAGNETISM; it can also be used to deter­mine VARIATION.
3071
magnetometer: vector airborne
A FLUX-GATE MAGNETOMETER which measures the intensity and direction of the EARTH'S MAGNETIC FIELD from an aircraft.
3072
magnetometer survey
See SURVEY.
3073
magnetometric zero balance
A MAGNETIC OBSERVATORY instrument used for accurate measurement of the verti­cal component of the EARTH'S MAGNETIC FIELD.
3074
magnetostriction
The PHENOMENON wherein ferromag­netic material experience an elastic strain when subjected to an external MAGNETIC FIELD. Also, the converse... more
The PHENOMENON wherein ferromag­netic material experience an elastic strain when subjected to an external MAGNETIC FIELD. Also, the converse PHENOME­NON in which mechani­cal stresses cause a change in the MAGNETIC INDUCTION of a ferromagnetic material.
3075
magnetostriction transducer
See TRANSDUCER.
3076
magnetron
An electron tube for converting direct-current energy into radio-frequency energy by means of a MAGNETIC FIELD.
3077
magnification
The apparent enlargement of anything. In optics, the term relates to the properties of LENSES and LENS SYSTEMS to produce an IMAGE which dif... more
The apparent enlargement of anything. In optics, the term relates to the properties of LENSES and LENS SYSTEMS to produce an IMAGE which differs in dimension from the related object.
3078
magnifying glass
A LENS or combination of LENSES that increases the apparent size of an object seen through it.
3079
magnifying power
The ratio of the apparent length of a linear dimension as seen through an optical instru­ment to that seen by the unaided eye. Sometimes sho... more
The ratio of the apparent length of a linear dimension as seen through an optical instru­ment to that seen by the unaided eye. Sometimes shor­tened to power.
3080
magnitude
The importance, quality or size of some­thing. In ASTRONOMY, relative brightness of a CELESTIAL BODY. According to the accepted classifica­t... more
The importance, quality or size of some­thing. In ASTRONOMY, relative brightness of a CELESTIAL BODY. According to the accepted classifica­tion, a STAR of the 1st magnitude is a hundred times as bright as a STAR of the 6th mag­nitude (the faintest STAR that can be seen with the unaided eye) and the dis­tribution of magnitudes is logarithmic in terms of brightness. Thus each reduction in magnitude means an increase of brightness of about 2 1/2.