12.2.4 If necessary, reconnect the pipet to the vacuum
system. Switch on the vacuum source and regulate to ensure an
air flow rate of 15 L/h in the vacuum regulator. Check that the
U-tube manometer (if used) indicates a 200 6 1 mm depression (2 6 0.05 kPa) or that the electronic vacuum regulator
indicates a pressure of 2 6 0.05 kPa.
12.2.5 Press the start button immediately after insertion of
the test jar assembly. If the cloud point is known, aspiration of
the specimen through the filter may be set to start when it has
cooled to a temperature not less than 5°C above the cloud
point. The apparatus will carry out the test procedure filtering
the specimen at each 1°C decrease if temperature and measuring the filtering time. If the time to reach the 20 mL mark
exceeds 60 s on the first filtration, the test is to be abandoned
and repeated on a fresh specimen starting at a higher temperature. The apparatus will record the first temperature at which