Good Measurement Practices
3
General Considerations
Apertured Cells or Cuvettes
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 in sensitivity. See
Figure 7
for recommended cells and
Figure 8
for cells you should not use with the instrument.
Quartz cells
Quartz cells with black apertures*
Figure 7
Recommended cells
* Quartz cells with black apertures smaller than 2 mm, when used with a multicell
C A U T I O N
transport, can lead to measurements of poor reproducibility.
Agilent Cary 8454 UV-Visible Spectroscopy System Installation Guide
41