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.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.

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.
An Illustrated Dictionary of Aviation Copyright © 2005 by The McGraw-Hill Companies, Inc. All rights reserved
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

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.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
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References in periodicals archive ?
To find the actual variometer drifts in all three axes, we have utilized a least-squares fitting method, which generally minimizes the difference [B.sub.Diff] between the scalar reading [B.sub.BDV] at the BDV observatory and the calculated scalar value at PLM from the three individual components [B.sub.1], [B.sub.2], [B.sub.3].
Vlk, "Low-noise magnetic observatory variometer with race-track sensors," IOP Conference Series: Materials Science and Engineering, vol.
Caption: Figure 5: Sketch of the situation at KEL station: the variometer sensor (0) is located approximately 25 m from a frequent local street, which is running roughly in E-W (x) direction.
Improving Earth's Magnetic Field Measurements by Numerical Corrections of Thermal Drifts and Man-Made Disturbances
The variometer was constructed in a cylindrical plastic food storage jar, 12cm in diameter and 18cm high.
In both fluxgate and variometer sensors, a temperature sensor was co-located with the sensor.
Figures 6 and 7 show variometer and fluxgate observations taken on 2011 April 6 & 7.
The figures show that both sensors see quite small changes in magnetic declination (for the variometer) and the east-west field strength (for the fluxgate).
The Hall-effect sensors in the variometer, by comparison, are easier to use and show no detectable variation with temperature.
Note that while the fluxgate sensors should vary (almost) linearly with the magnitude of disturbances in the magnetic field, the voltages from the variometer will not have so simple a relationship (but, for detecting auroral conditions, this is not a problem).
A comparison of two simple magnetometers

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