PerkinElmer Photovac 2020, Руководство пользователя

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2020 Software Manual
78
Response Factors for Gases and
Vapors
General Information
In situations where only a single pure compound is present in air,
2020 should be calibrated with a standard of that specific compound
as span gas. 2020’s 15 Cal Memories can be used to store
calibration information for 15 different span gases.
The displayed reading will always be influenced by any other
photoionizable compounds present in the air sample.
NOTE: Even if 2020 has been calibrated with a specific compound, its
response is not specific and the presence of another ionizable
impurity may render the numerical result invalid.
It is often impractical to carry a range of different standards into the
field. Approximate results can be obtained by calibrating 2020 with
the recommended span gas and entering the appropriate response
factor. The response factor is based on the ratio of the response of
the specific compound to the response of the span gas. The
response factor multiplies 2020’s reading then displays and records
it.
Page 169 provides a list of response factors from which
approximations can be made for guidance purposes. Data
extrapolated from the use of response factors must be regarded as
interim and approximate only. This list should be used only for
concentrations up to 500 ppm of the specific compound, as response
factors change with concentration.
Using Response Factors
To use the response factors stored in your library:
1. Select “Set”, “Cal” and “Mem”.