Hoefer VP200 - Manual (Page 14)

Installing a cold trap
You may install a cold trap, such as a vacuum
flask in dry ice, between the gel dryer and the
pump. A cold trap is not required to protect the
pump, but it minimizes the amount of vapor
released to the atmosphere.
1
Once the cold trap is in place, create a vacuum reser-
voir in the front end of the system, at the pump and
cold trap. Then open the valve to the back end of the
system—the dryer and gel stack—to quickly seal the
rubber overlay against the heater surface.
2
Once the gel stack is properly placed according to
the instructions accompanying the gel dryer, turn on
the mains power switch for the gel dryer, then turn on
the mains power switch on the front left part of the
vacuum pump body. Watch for the seal between the
clear silicone rubber overlay and the gel.
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