‘petrol vapour capture efficiency’ means the amount of petrol vapour captured by the Stage II petrol vapour recovery system compared to the amount of petrol vapour that would otherwise be emitted to the atmosphere in the absence of such a system and expressed as a percentage;

‘vapour/petrol ratio’ means the ratio between the volume at atmospheric pressure of petrol vapour passing through the Stage II petrol vapour recovery system and the volume of petrol dispensed;

The apparatus must be able to regulate various amounts of steam and produce a constant amount of steam over a given period of time.

5.2. Vapour-collection detection Loading must not be permitted unless the vapour-collection hose has been connected to the vehicle and there is a free passage for the displaced vapours to flow from the vehicle into the plant vapour-collection system.

At terminals which load petrol onto vessels, a vapour incineration unit may be substituted for a vapour recovery unit if vapour recovery is unsafe or technically impossible because of the volume of return vapour.

4.1. Steam distillation apparatus consisting of:1. a steam generator; the steam must be free of carbon dioxide; 2. a flask with steam pipe; 3. a distillation column; 4. a condenser.This equipment must pass the following three tests:(a) Place 20 ml of boiled water in the flask. Collect 250 ml of the distillate and add to it 0,1 ml of 0,1 M sodium hydroxide solution (3.2) and two drops of the phenolphthalein solution (3.3). The pink colouration must be stable for at least 10 seconds (i.e. steam to be free of carbon dioxide) (b) Place 20 ml of a 0,1 M acetic acid solution in the flask.