Environmental Conditions - PerkinElmer aanalyst 200 User Manual

Preparing Your Lab

Environmental Conditions

The laboratory in which the AAnalyst 200 is located must meet the following conditions:
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A corrosive-free environment.
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The instrument will operate with a laboratory temperature between 15 and 35 °C (59-95 °F)
with a maximum rate of change of 3 °C (5 °F) per hour.
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The environment should be relatively dust-free to avoid sample and instrument
contamination problems.
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Free of excessive vibration.
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Free of direct sunlight.
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The relative humidity should be between 20% and 80%, noncondensing.
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Two types of flames are commonly used for atomic absorption flame analysis: air-acetylene
or nitrous oxide-acetylene. Air acetylene is the preferred flame for the determination of
about 35 elements by atomic absorption. The temperature of the air-acetylene flame is
approximately 2300 °C (4200 °F). For most air-acetylene flames, the acetylene flow used is
about 4 liters per minute ( or 0.14 cubic feet/min). Using a heat combustion value of 1,450
BTU per cubic foot, the heat given off would be approximately 12,300 BTU per hour.
The nitrous oxide-acetylene flame has a maximum temperature of approximately 2800 °C
(5100 °F) and is also used for the determination of elements which form refractory oxides. It
is also used to overcome chemical interferences that may occur in flames of lower
temperatures. For the nitrous oxide-acetylene flame, the acetylene flow is about 14
liters/min (or 0.5 cubic feet per min.). Using a heat of combustion value of 1,450 BTU per
cubic foot, the heat given off would be approximately 43,000 BTU per hour.
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