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Agilent 240/280 Series AA User's Guide
Ensure that the spray chamber and liquid trap are kept clean.
If dirty solutions are being analyzed (for example, engine oils),
ensure that the spray chamber, liquid trap, float and drain tube
are regularly cleaned and flushed with a suitable solvent so that
sludge does not build up in the parts.
Ensure that the correct O-rings are used on the burner, nebulizer
block and nebulizer, and that they remain undamaged.
Damage to O-rings in the spray chamber can result in the leakage
of gas which can be ignited by the flame and in turn set fire to the
spray chamber.
Damage to O-rings in the nebulizer can allow leakage of the
oxidant which can reduce the total flow of gas through the
burner slot and so increase the possibility of a flashback
occurring.
The liquid trap must be filled with the same solution as the
matrix used for the standards and samples.
The drain tube must be attached to the lower nipple of the liquid
trap, and it must slope downwards all the way to the drain vessel
so that the waste liquid drains smoothly.
The end of the drain tube must not be allowed to drop below the
level of the liquid in the vessel. (Conversely, the level of liquid
must not be allowed to rise sufficiently to cover the end of the
tube.)
When using organic or toxic liquids in the spray chamber, a vent
tube must be attached to the upper vent nipple of the liquid trap.
It must slope downwards (running parallel to the drain tube) to
prevent it becoming blocked should any liquid drain out, and be
vented to an active exhaust system.
All of the above points must be observed because a sudden surge
of waste liquid can affect the pressure in the spray chamber and
result in a flashback.
Since N
O is stored in the cylinder under pressure as a liquid,
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when it expands through the regulator it can cool the regulator
sufficiently to form ice on the outside and prevent it from
operating correctly.
Prevent freezing by using a heater on the N
supply cylinder. Contact the supplier of the regulator for a
suitable heater.
Safety Practices and Hazards
O regulator on the
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