Buchi DuMaster D-480, Руководство по эксплуатации

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Operating instructions DuMaster D-480 ©BÜCHI Labortechnik AG
7 - Using the instrument 142
Note
The first blank value is always too high after prolonged breaks between measurements or after
maintenance. If you want to perform an exact blank value determination, you must exclude the first
blank value from the calculation. Use a different name for the first blank value sample than the key
word in order to exclude the sample from the calculation.
Determining blank values
Proceed as follows:

If you have not already done so, set the mode of blank value determination. For that purpose,
open the "Configure Calculations" dialog in the operating software by selecting
Options >
Settings > Calculation
.

Define the mode of blank value determination:
If you select the following in "Blank value determination"

... ...select "sequentially" a separate blank value is computed for every element for every
group of blank value samples; this value is entered in the respective blank value column
until the next group of blank value samples.

... ...select "entirely" all blank value samples in the series are used to compute the blank
value. This blank value is then applied to all samples in the series.

Then click
OK
to save your settings.

Usually, do
not
place a sample on the carousel.
Only exception: When determining blank values of sample additives or packing materials, place a
blank sample on the carousel. Cf. Types of blank value determination and their settings.

Enter the following for the sample in the sample view (text view) on the PC:

Name:
Blnk

Weight:
1 mg

Click
Method
in the line of the appropriate sample. An arrow is displayed with which you can
open a dropdown list with various methods.

Select the appropriate method for the blank value sample. Cf. Types of blank value determination
and their settings.

Start the blank value determination via
System > Auto run
.

Once the measurements are finished you can compute the blank value. To do so, open the
"Blank values" dialog by selecting
Math. > Blank values > Calculate
.

If "total" blank value calculation has been selected, the "Blank values" dialog will now open. Here,
the blank value just computed is displayed. Click
OK
to accept the blank value.

The blank value is now automatically used for the following measurements.
Determining the daily factor
Why is the daily factor determined?
The daily factor is determined in order to correct calibration according to atmospheric conditions (air
pressure, temperature) at the time of performing the analysis. The daily factor is factored into
subsequent measurements.
When must daily factor samples be measured?
Daily factor samples are measured on the following occasions:

During routine measuring work, once a day.

When the carousel is full daily factor samples are measured at the end (and between if
necessary) in order to check the condition of the instrument.