Hitachi ZA3000 Series, Инструкция по эксплуатации

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10.1
10 - 13

Gas Flow (mL/min)
Enter a carrier gas flow rate in the ashing stage.
Usually there is no need for changing 200 mL/min.
Input value: 0, 10, 30, 200 mL/min

Gas Type
Select the desired kind of carrier gas in the ashing stage
(between Normal and Alternate).
Usually select Normal (argon gas).
NOTE : For using the alternate gas, a stage for replacement
with the normal gas is necessary before atomization.
Setting is required in [Ash addition].

Background Detection
Background detection in an ashing test is a function for
monitoring the reference signal (REF) in the ashing
stage and judging the timing of the end of ashing from a
change in the reference signal, thereby setting an
ashing time.
From a sample, the concomitant substance evaporates
in the ashing stage and the vapor absorbs the beam
from the light source, so background absorption occurs.
This may cause a rise in the reference signal. When
the concomitant substance is vaporized completely, the
background absorption due to the vapor will end.
Therefore, the reference signal falls and returns to the
baseline.
In the background detection function, it is first judged
that the background was detected upon detection of a
rise in the reference signal beyond the [Detection Start]
level set in the Temp. Program Test Conditions window.
Then, it is judged that the background absorption ended
when the reference signal fell below the set [Detection
End] level, and the background detection is terminated.
On termination of the background detection, sample
ashing is judged to be completed and a time period
taken from the start of measurement and the end of
background detection is reflected as a necessary ashing
time onto the temperature program.
When you put a check mark for [Background Detection]
by clicking its check box, the background can be
detected under the set conditions.