Logitech Ltd IU30 Impregnation Unit Operation and Maintenance ...

2.3 Checking the Vacuum
Fit the resin feed system to the resin and sample chambers, as shown in the diagram for
section 3.1.3, ensuring that the O‐rings, shown in section 3.1.1, are in place contacting the
top of the glass lid (16). Check visually that the O‐rings on the sample chamber (1) are in
place and that the resin chamber (2) is sitting squarely under the glass lid (16) on its spring
loaded base. Ensure that the resin and sample chamber valves (10, 12) and the resin and
sample chamber vents (11, 13) are closed.
Switch on the machine using the mains switch at the side by the electrical inlet. The pump
will start and the mains indicator light (8) on the pirani gauge (9) will glow green. The pirani
gauge (9) will progressively reduce in reading to the ultimate vacuum achieved by the pump
over a period of up to half a minute. This should be in the region 10 ‐2 to 5x10 ‐2 mbar.
Slowly open the sample chamber valve (12) ‐ the sample chamber (1) will start to pump
down. On a new machine the vacuum will gradually build over a period which may be as
long as half an hour, depending on water vapour etc., which has accumulated in transit
(after this first pump down the sample chamber should evacuate in under five minutes). If
the vacuum fails to start building, ensure that all O‐rings are sitting on clean surfaces.
Repeat this check after opening the resin chamber valve (10), so that both chambers are
evacuated. In both cases the ultimate vacuum reach will depend on atmospheric and other
conditions but should be in the region of 5x10 ‐2 mbar to 10 ‐1 mbar.
2.4 Health & Safety
When operating this unit the operator must be aware of the risks involved when working
with resins and vacuum pressure.
a) The unit is operated under sufficient vacuum pressure to accelerate the exothermic
reaction in the resin when out gassing. Care must be taken to slowly control the rate
of expansion of the resin bubbling up or effervescing to retain it inside the mixing
vessel. This is done by manually adjusting rate of air removal via the vacuum/air
control valves.
b) The vacuum pump exhaust port emits oil vapour and must be vented correctly
through a suitable oil mist filter (see separate vacuum pump manual if supplied with
the machine) or to the facility exhaust system to prevent oil mist in the working
area.
c) The system is not sensitive to vibration and can be installed on a standard bench
which will support the weight (74kg).
Logitech Ltd, IU30 Impregnation Unit – Manual BE‐03‐02‐2 –version v0211 ‐ Page 10