Smoke School Lecture Course

Logout
logout

Bookmark

Bookmark this Page

Contact

Contact AeroMet

Section 1.3

Visible Emissions & Opacity Defined

Online Lecture Demo Page
Click here to return to website.

The terms “visible emissions” and “opacity” will be used frequently throughout this course. Let’s take a look at exactly what they mean.


Visible Emissions

Smoke exiting a stack at a power plant

A visible emission is the visible particulate matter that occurs as the result of a process. Smoke exiting a stack at a power plant is a visible emission

Gravel Road

Dust produced from driving down a gravel road is a visible emission

Smoke from a chimney

Smoke from the chimney of your fireplace is a visible emission



Opacity

When you’re talking about visible emissions, opacity is the degree to which light is blocked by the emissions. When you are observing emissions there is always a background behind the smoke plume. This background can be anything, but ideally it should contrast with the emissions you are observing.

Tree as a background Tree as a background
Sky as a background Sky as a background
Building as a background Building as a background


Video Demonstration of Opacity