Prices 2018 - Wavenumber Units, K is for wavenumber — agile, Wavenumber , sometimes called the propagation number , is in broad terms a measure of spatial scale . it can be thought of as a spatial analog to the temporal frequency , and is often called spatial frequency . it is often defined as the number of wavelengths per unit distance, or in te. Wavenumbers and frequencies - department of chemistry, Centimeters as a measure of the frequency of radiation. this unit is called a wavenumber and is represented by . ν and is defined by 1 c. ν ν λ = = example: the wavelength of the red line in the hydrogen spectrum is approximately 656.5 nm. this corresponds to 656.5 x 10-9 m x 102 cm/m or 656.5 x 10-7 cm or 1.523x104 cm-1.. Wavenumber to wavelength conversion | sciencing, The wavenumber has units of 1/distance, or distance − 1. for wavelengths expressed in meters, this is m − 1, and if the wavelength is expressed in cm, the units of the wavenumber are cm − 1..