Back مقياس لوغاريتمي Arabic Логаритмична скала Bulgarian Escala logarítmica Catalan Logaritmická stupnice Czech Logarithmische Darstellung German Λογαριθμική κλίμακα Greek Logarithmic scale English Escala logarítmica Spanish Logaritmiline skaala Estonian Eskala logaritmiko Basque
A logarithmic scale is a scale used when there is a large range of quantities. Common uses include earthquake strength, sound loudness, light intensity, spreading rates of epidemics, and pH of solutions.
It is based on orders of magnitude, rather than a standard linear scale. The value of each mark on the scale is the value at the previous mark multiplied by a constant.
Logarithmic scales are also used in slide rules for multiplying or dividing numbers by adding or subtracting lengths on the scales.
The logarithmic scale can be helpful when the data cover a large range of values – the logarithm reduces this to a more manageable range.
Some of our senses operate in a logarithmic fashion (multiplying the actual input strength adds a constant to the perceived signal strength, see: Stevens' power law). That makes logarithmic scales for these input quantities especially appropriate. In particular, our sense of hearing perceives equal multiples of frequencies as equal differences in pitch.
On most logarithmic scales, small multiples (or ratios) of the underlying quantity correspond to small (possibly negative) values of the logarithmic measure.