Page 11 - Catalogue - cuvettes and solid-state calibration standards

A to Z – cuvette terminology explained

Borosilicate glass

 Contains large amount of boron trioxide and silicon dioxide. It has a very low thermal expansion coefficient and
is, therefore, resistant to thermal shock.

Circular dichroism

 Measures differences in the absorption of left-handed polarized light versus right-handed polarized light which
arise due to structural asymmetry.

Coefficient of thermal expansion

 Refers to how an object’s size is affected by changes in temperature. Specifically, it measures the fractional
change in size per degree change in temperature at a constant pressure. Although several types of coefficients
have been developed, for example volumetric, area and linear, the one used depends on the particular
application and on which dimensions are considered important. For solids (cuvettes) we are primarily
concerned with changes to lengths or areas.

Colorimetry

 Is a method for analysing, quantifying and describing colour perception. Although close to spectrometry,
colorimetry is different in that it emphasises reducing spectra to the physical correlates of colour perception.
These are commonly enshrined in the CIE 1931 XYZ colour space values.

Demountable cells

 Comprise two or more glass or quartz components that can be taken apart (demounted) and reassembled.
These cuvettes are easy to clean and have a very low volume. So when sample size is critical, this type of cell
is very convenient for retrieving your sample.

Fused Silica Quartz

 Has high thermal shock resistance and is extremely resistant to highly-concentrated acids, with the exception
of hydrofluoric acid which has a negative effect on the material even at low concentrations.

Fusing

 The FireflySci cuvettes are manufacturer by fusing – the individual glass or quartz components are melted
together (fused) at extremely high temperatures. Glass frit is not used in the production of their cuvettes.

Graded Seal

 In order to attach glass apparatus to a quartz cuvette or to modify it in any way it’s necessary to have a robust
and reliable transition from the one material to the other. Graded Seals have various “middle glasses” with
different coefficients of thermal expansion fused into them. In this way, the thermal shock initiated when the
glass blower attaches the modification to the glass end of the tube is cushioned and the quartz cell is protected
from damage.

Lightpath

 Also known as pathlength, this is the distance between the inside of the optically polished windows of a
cuvette. It is measured in mm, the FireflySci products range between 0.01 mm and 200 mm depending on cell
type.

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All prices are shown in Euro and are subject to VAT where applicable.