variometer


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variometer

[‚ver·ē′äm·əd·ər]
(electromagnetism)
A variable inductance having two coils in series, one mounted inside the other, with provisions for rotating the inner coil in order to vary the total inductance of the unit over a wide range.
(engineering)
A geomagnetic device for detecting and indicating changes in one of the components of the terrestrial magnetic field vector, usually magnetic declination, the horizontal intensity component, or the vertical intensity component.

Variometer

 

in radio engineering, a variable-inductance coil designed for tuning oscillatory circuits. The type of variometer used in the 1920’s and 1930’s was divided into two sections connected in series: a fixed outer coil (the stator) and a movable inner coil (the rotor). The inductance of the variometer is equal to the sum of the inductances of the sections and the mutual inductance between them, which changes significantly when the rotor is turned 180°. This type of variometer was widely used to retune the frequency of the oscillatory circuit of a radio receiver. The variometer subsequently lost its original form and use and is now used in radio receivers as an inductance coil containing within its winding a core made of a magnetic dielectric that changes the induction within insignificant limits in order to adjust the frequency of the oscillatory circuit.

variometer

variometerclick for a larger image
Two types of variometer.
An instrument that is a sensitive rate of climb and descent indicator. Used in sailplanes and gliders, it indicates climb and descent almost instantaneously, unlike conventional vertical speed indicators, which suffer from lag.
References in periodicals archive ?
CTU and IG CAS took the opportunity to install a fluxgate variometer instrument [4] in the already magnetically prescreened and prepared locality.
Although the noise at BDV station is very low, the used instrument (DMI fluxgate variometer) has large intrinsic noise, so actually, during the quiet night periods (with almost no electric train traffic), the PLM data are less noisy due to the used variometer.
To be able to detect, mark, and possibly remove the passing car's magnetic signature, an axial ([dB.sub.y]/dy) fluxgate gradiometer has been created in N-S direction by placing a second sensor coaxial to the variometer head.
Utilizing a "full-field" variometer, thus measuring in a feedback loop all the three vector components of the magnetic field at once, allows us for calculation of the total magnetic field (the scalar vector magnitude).
As with most gliders, it was equipped with a more traditional variometer on its instrument panelas a back-up.
If you don't have a variometer you can be rising and think that you are flying straight.
The variometer is the oldest and simplest instrument for monitoring the Earth's magnetic field.
The simplicity and low cost of the basic variometer are advantages but the lack of automatic recording of the output is its disadvantage.
In contrast to the variometer, the fluxgate is a much more complex, and recent (developed in the 1930s), sensor.
For this paper, a fluxgate sensor and a home-made variometer were installed in the author's study.
Speed-to-fly information is presented to the pilot by placing a speed-to-fly ring (Mac-Cready ring) around the variometer dial, referring to a table or chart or using an electronic flight computer displaying the data.