# Napierian absorbance

> natural logarithm of the ratio of incident to transmitted radiant flux

**Wikidata**: [Q85664557](https://www.wikidata.org/wiki/Q85664557)  
**Source**: https://4ort.xyz/entity/napierian-absorbance


## References

1. ISO 80000-7:2019 Quantities and units — Part 7: Light and radiation