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Because voltage and resistance can themselves be measured to extraordinary precision using quantum electrical effects (the Josephson effect and the quantum Hall effect), a Kibble balance effectively measures mass in terms of the Planck constant, h. The relationship, in its simplified form, is: . where m is the test mass, g the local gravitational acceleration (independently and precisely measured at the balance’s location), v the coil’s velocity in the moving phase, and U and I the voltage and current measured electrically. Combined with the quantum electrical measurements of U and I in terms of h , this equation is what let NIST’s NIST-4 Kibble balance measure the Planck…
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Symbol g
g is part of the quantity the equation computes from the expression on the right.
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Equation 1 · Scientific Methods
From Origins to Frontier: A History of Scientific Instruments and Metrology
This equation states an equality: the expressions on both sides have the same value under the article’s assumptions.
Because voltage and resistance can themselves be measured to extraordinary precision using quantum electrical effects (the Josephson effect and the quantum Hall effect), a Kibble balance effectively measures mass in terms of the Planck constant, h. The relationship, in its simplified form, is: . where m is the test mass, g the local gravitational acceleration (independently and precisely measured at the balance’s location), v the coil’s velocity in the moving phase, and U and I the voltage and current measured electrically. Combined with the quantum electrical measurements of U and I in terms of h , this equation is what let NIST’s NIST-4 Kibble balance measure the Planck…
Meanings in this article
- : the test mass.
- : the coil’s velocity in the moving phase.
- : the voltage and current measured electrically.