Analyzing Samples
Agilent 4200 FlexScan FTIR Operation Manual
25
The response of the detector is reported on the MicroLab PC and
MicroLab Mobile software on the Diagnostics page, available from the
Advanced Features page; it is labeled Energy. The energy value has a
range from 1000 to 30,000.
First, select the reference standard that is most similar to the sample;
the diffuse standard should be used for samples that scatter light,
while the mirror standard should be used for samples that reflect
light. With the appropriate reference in place, observe the energy
value. The value should be close to 26,000 with the reference
standard in place. If the energy value is below 23,000 or above 29,000
counts, click the Gain Adjust button.
The Gain Adjustment screen shows the Energy value at the top and
has up/down arrows to adjust the gain. With the reference in place,
adjust the gain to bring the energy to 26,000 counts. Once the
appropriate gain is set, it can either be saved as the System Default
or Method gain. The System Default gain is used for all methods,
while the Method gain is used only for the currently selected method.
Once the gain has been set, it is useful to check the energy from a
sample. The sample must have energy greater than 1000. Also, the
sample should have energy less than that of the reference.
Steps
The steps involved in performing an external reflectance analysis are:
1
Collect a background spectrum using the reflectance cap.
2
Collect a sample spectrum.
Collecting a background spectrum
To ensure accuracy of the measurement, it is recommended that the
system is configured in the software to collect a background
spectrum before every sample is analyzed. This provides a baseline
profile of the system conditions using the gold reference cap. By
collecting a background automatically before each sample
measurement, negative effects of changes in the environment can be
avoided.
Summary of Contents for 4200 FlexScan
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