12.1.5 If the jacket is not an integral part of the cooling bath,
place the jacket vertically to a depth of 85 6 2 mm in the
cooling bath (see 6.1.10), which is maintained at the temperature of –34 6 0.5°C.
12.1.6 Insert the test jar assembly in a stable vertical
position into the jacket.
12.1.7 With the stopcock (see 6.1.11) open to atmosphere,
connect the pipet to the vacuum system (see 6.1.12 and 6.1.13)
by means of flexible tubing attached to the stopcock (see Fig.
1). Switch on the vacuum source and regulate to ensure an air
flow rate of 15 L/h in the vacuum regulator (see 6.1.13). Before
starting a test, check that the U-tube manometer indicates a 200
6 1 mm of water depression (2 6 0.05 kPa).
12.1.8 Start the test immediately after inserting the test jar
assembly into the jacket, but if the cloud point of the sample is
known, it is permitted to wait until the specimen has cooled to
a temperature of not less than 5°C above its cloud point.
12.1.9 When the specimen temperature reaches a suitable
integer value, turn the stopcock (see 6.1.11) so that the filter
assembly is connected to the vacuum source, causing the
specimen to be drawn through the wire mesh into the pipet;
simultaneously start the stopwatch