wtw PhotoLab Spektral, Operating Instructions Manual

Page: 117 / 162

87
12 Zero adjustment
12
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adj
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Zero adjustment is necessary
●
after changing the lamp
●
after the error message PhotoCheck occurs
(AQA1)
●
after changing the Memory Card
●
on initial commissioning
●
if the photometer was mechanically stressed, e.g.
percussion, transport
●
if the ambient temperature changed by more than
5 °C since the last zero adjustment
●
at least every six months.
When performing the zero adjustment with a round
cell observe the following points:
When performing the zero adjustment observe the fol-
lowing points:
●
Only use a clean, scratch-free round cell with dis-
tilled water. A prepared zero cell is provided with
your photometer. In addition, a prepared zero cell
is contained in the scope of delivery of the Photo-
Check (article 14693).
●
If the round cell is visibly contaminated, or at least
every 24 months, clean and refill it (minimum
filling level 20 mm). Then check the cell for
scratches.
When performing the zero adjustment with a rectan-
gular cell observe the following points:
●
With rectangular cells, the adjustment must be
made using the same cell type (manufacturer) as
for the measurement. This is important because
glass of different manufacturers has different
absorption behavior. When changing the cell type
always repeat the zero adjustment with the new
type.
●
Clean the rectangular cell before performing the
zero adjustment and fill it with distilled water (mini-
mum filling level 20 mm).
●
For measurement, always insert rectangular cells
in the cell shaft with the same orientation as during
the zero adjustment (e.g. cell labeling always on
the left side).