Apertured Cells - Agilent Technologies Cary 8454 Operator's Manual

Good Measurement Practices 4
General Considerations

Apertured Cells

In applications where sample volume is limited, apertured or microcells are
used. The width of these cells is reduced to reduce the volume and the blank
part of the cell must be blackened to avoid unwanted transmission and
reflection through the side walls. If the side walls are not blackened the result
will be poor photometric accuracy and, if different concentrations are
measured, poor linearity.
The disadvantage of apertured and microcells is that part of the light beam is
blocked. Not all the light passes through the sample and there can be some loss
of sensitivity. See Figure 5 for recommended and Figure 6 for cells you should
not use with the instrument.
Quartz cells Quartz cells with black
Figure 5 Recommended cells
* Quartz cells with black apertures smaller than 2 mm, when used with a multicell
CAUTION
transport, can lead to measurements with poor reproducibility.
Agilent Cary 8454 UV-Visible Spectroscopy System Operator's Manual 55