BUCHI DuMaster D-480 - Manual (Page 145)

Operation Manual D-480 ©BÜCH Labortechnik AG
7 - Using the instrument 145
 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 (on page 143).
 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.
Ways of determining the daily factor
There are three ways to determine the daily factor:
 You can compute the daily factor manually. This makes sense if you do not want to define the
substance as a factor sample.
 You can selectively trigger determination of the daily factor:
 You can then choose the time for determining the daily factor yourself.
 You can choose the standard samples with which the daily factor is determined yourself.
Condition: The daily factor samples must have a name defined in Options > Settings >
Standards and the standard substance must be enabled as a factor sample.
 Daily factor determination can be set to fully automatic.
 If you measure substances defined as factor samples, they are recognized and the daily
factor is automatically computed from them.
 Because the daily factor is determined several times a day, it will also offset any
fluctuations in the course of the day. Condition: The daily factor samples must have a name
defined in Options > Settings > Standards and the standard substance must be enabled
as a factor sample.
Computing the daily factor by hand
Proceed as follows:
 Measure any substance, that need not be defined in Options > Settings > Standard samples.
 Compute the daily factor. Daily factor = (theoretical content / actual content).