摘要 |
Using a smoke generator, it is possible to determine flows in gaseous media. Smoke generators of a pyrotechnic composition are presently available. It is desirable that it should be possible to turn off the smoke generator when it has fulfilled the purpose for which it is being used. With pyrotechnic smoke generators, this requires water. This is a disadvantage. The present invention overcomes this by using a relatively thick thread that can be ignited at one end. On ignition, a flame is formed. When the flame is blown out, smoke is generated. Where said thread functions in conjunction with a sleeve (labelled "7" in the accompanying figures), smoke generation can be terminated by fully withdrawing the smoke generating end into the sleeve. This results in total extinction of said end. |