Variometrum ((new)) | PLUS • 2025 |

Modern "varios" use solid-state pressure sensors, GPS, and accelerometers to compute not just vertical speed, but also (how fast you are climbing relative to the surrounding air) and relative wind . Yet, the fundamental algorithm—measure total energy change, filter out pitch-induced noise—remains unchanged from the 1960s glider revolution. Why "Variometrum" Still Matters The word itself suggests something grander than a gauge: metrum (measure) of varius (change/variety). The variometrum is not just a measure of altitude change; it is a measure of the atmosphere’s hidden structure. It reveals what the eye cannot see—invisible columns of rising heat, the subtle sinking of cold air over a forest, the wave-like ripple of air over mountains.

A true variometrum for soaring must ignore exchanges between potential and kinetic energy. It should only respond to external energy sources—namely, . variometrum

Pull back on the stick in a glider, and you trade airspeed for altitude. The aircraft climbs briefly, but loses kinetic energy. The standard variometrum reads a joyous "climb!" even though the glider is actually decelerating and will soon sink back down. This false reading leads pilots into "thermalling" a momentary pitch-up, not a real rising column of air. Modern "varios" use solid-state pressure sensors, GPS, and

Enter the (also called a TE variometer or compensated variometrum ). The Principle of Total Energy The total energy of an aircraft is: [ E_{total} = E_{potential} (altitude) + E_{kinetic} (speed) ] The variometrum is not just a measure of

For a pilot, mastering the variometrum means learning to feel the breath of the planet. For an engineer, it is a perfect example of analog computation using pneumatics. For everyone else, it stands as a reminder that the simplest instruments—a diaphragm and a leak—can reveal the most profound truths about the world above. The variometrum is far more than a "vertical speedometer." From its humble pneumatic origins to its total-energy evolution, it remains the definitive instrument for understanding and exploiting the invisible ocean of air in which all aircraft swim. Whether you call it a VSI, a vario, or by its classical name, it is truly the vertical compass of the sky.