Soldering terminology

Fluxes that employ rosin (coniferous resin) as the main component smell when dissolved. The quantitative concentration of an odorous substance in air is known as the odorous substance concentration value. If an odorous gas is diluted thousand fold in the ambient air and is no longer perceptible, then this substance has "an odor threshold of 1000". The greater the degree of dilution must be, the stronger the smell of the respective material is. The dilution air flow used in this case is regulated by a special odor- pump placed in an activated carbon tank in order to eliminate any traces of odorous substances. The test whether an odor is present or not is carried out by a group of six to nine subjects, mostly women over the age of 20.