XD 7500
Operation
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ba77191e01 - 71310060
04/2018
Validity of the zero
adjustment
The data of the zero adjustment is stored in the photometer separately for
each cell type. As long as the data is valid, it is automatically used again after
a temporary change to a different cell type. The validity depends on the
respective mode:
* The photometer displays that a zero adjustment is available and the time it was carried
out. You can then decide whether to use this zero adjustment or carry out a new zero
adjustment.
When to repeat the
zero adjustment?
We recommend to repeat the zero adjustment in the following cases:
If the photometer was subject to mechanical stress such as strong shock
or transport
If the ambient temperature changed by more than 5 °C since the last zero
adjustment
At least once per week
With use of anew cell type (different manufacturer, different glass type)
Basically each time you want to measure with the highest possible accu-
racy.
Mode
Validity of the zero adjustment
Absorbance / % Transmission
Till the next zero adjustment with the
same wavelength *
Concentration
(user-defined
methods) and
Special / Multi
wavelengths
Till the next zero adjustment for the same
method *
Kinetics
Till another kinetic profile is loaded
Till the
Kinetics
mode is exited or the pho-
tometer is switched off
