In telecommunications and fiber optics, ovality or noncircularity is the degree of deviation from perfect circularity of the cross section of the core or cladding of the fiber.

The cross-sections of the core and cladding are assumed to a first approximation to be elliptical. Quantitatively, the ovality of either the core or cladding is expressed as , where a is the length of the major axis and b is the length of the minor axis. The dimensionless quantity so obtained may be multiplied by 100 to express ovality as a percentage. Alternatively, ovality of the core or cladding may be specified by a tolerance field consisting of two concentric circles, within which the cross section boundaries must lie.

In measurements, ovality is the amount of out-of-roundness of a hole or cylindrical part in the typical form of an oval.

In chemistry

In computational chemistry, especially in QSAR[1] studies, ovality[2] refers to, a measure of how the shape of a molecule approaches a sphere (at one extreme) or a cigar shape (at the other). Ovality is described by a ratio of volume to area:


O = Ovality
A = Area
V = Volume

The ovality of the He atom is 1.0 and that of HC24H (12 triple bonds) is ~1.7.

See also


  1. ^ Leach, Andrew R. (2001). Molecular modelling: principles and applications. Englewood Cliffs, N.J: Prentice Hall. ISBN 0-582-38210-6.
  2. ^ Hehre, Warren J.; William Sean Ohlinger (2008). Spartan'10 Tutorial and User's Guide. Irvine, CA: Wavefunction, Inc. ISBN 1-890661-41-4.