# Ringelmann scale

> scale for measuring the opacity of smoke

**Wikidata**: [Q7334848](https://www.wikidata.org/wiki/Q7334848)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Ringelmann_scale)  
**Source**: https://4ort.xyz/entity/ringelmann-scale


## References

1. Freebase Data Dumps. 2013