In many fields, such as mining or industry, it is very important to detect even the smallest air flows, in order to quickly and reliably evaluate the possible diffusion of dangerous substances. With the air flow test tubes, the source, direction and speed of the air flow are visible immediately.

Smoking sulfuric acid is located in the tubes. When the top of the tube is opened, a small rubber ball is used to pump air through the tube. This creates visible white smoke, which is carried on any existing air flows.

The air flow test tubes can be used until the "white smoke" has completely disappeared. If the test is completed before all the smoke disappears, the tube can be sealed again using the rubber cap provided.