Depending on the measurement requirement, different glass materials are available for the particular wavelength ranges. An original Hellma Analytics product can be identified from the material code on each cuvette.
The given transmission values are based on the measurement of empty cuvettes against air. Hellma guarantees a transmission of at least 80 % in the specified wavelength ranges of the glass materials.
Path length and tolerance accuracy is crucial for the quality of cuvettes. The tight tolerances make Hellma Analytics products ideally suited for collecting reliable and reproducible measurement results.
|Material||Optical Path Length||Tolerance|
|Quartz||0.01 mm to 0.05 mm||+/- 0.003 mm|
|Quartz||0.1 mm to 0.2 mm||+/- 0.005 mm|
|Quartz||0.5 mm to 20 mm||+/- 0.01 mm|
|Quartz||30 mm to 100 mm||+/- 0.02 mm|
|Special Optical Glass||0.1 mm to 10 mm||+/- 0.01 mm|
|Special Optical Glass||20 mm to 100 mm||+/- 0.03 mm|
|Optical Glass||10 mm to 20 mm||+/- 0.05 mm|
|Optical Glass||30 mm to 100 mm||+/- 0.1 mm|
Remark: These optical path lengths tolerances apply to absorption cells
If required, cuvettes can be spectrally calibrated into sets with equal transmission values with measurement uncertainty ±1%.
Cuvettes with an inside width greater than 5 mm can be polarimetrically checked on request. They are marked with a “P” and delivered with a test certificate confirming that the rotation of the polarization plane does not exceed 0.01 degrees.
QS indicates that “Quartz Glass High Performance” of the highest purity and homogeneity is used for the window. Because it is made from a silicon compound, it is also called synthetic quartz glass. We use specially selected quartz glasses which ensure transmission values of more than 82 % for a spectral range of 200 nm to 2500 nm for an empty cell.
UV indicates that “Quartz Glass” of highest purity and homogeneity is used for the window. These specially selected quartz glasses ensure transmission values of more than 80 % for a spectral range from 260 nm to 2500 nm for an empty cell.
QX indicates that “Quartz Glass Extended Range” of highest purity and homogeneity and free from OH absorption is used for the window. It is suitable for applications in the near infrared range up to approximately 4000 nm. We use specially selected quartz glasses which ensure transmission values of more than 82 % for a spectral range from 200 nm to 3500 nm for an empty cell.
OS indicates that “Special Optical Glass” is used for the window. This crown glass, specifically developed for Hellma, is made from exceptionally pure raw materials and gives improved transmission in the near ultraviolet range. An empty cell will give a transmission of more than 80 % over a spectral range from 320 nm to 2500 nm.
OG indicates that "Optical Glass" is used for the window. Here we use a colorless highly transparent crown glass in the form of drawn panes with fire-polished surfaces. The quality of the surfaces is so high that the components can be fused using the Hellma process without further grinding and polishing. An empty cell made of optical glass will give a transmission of more than 80 % over a spectral range from 360 nm to 2500 nm.
BF indicates the cells entirely made from borosilicate glass, the composition and properties of which are laid down by an international standard. This type of glass possesses a high chemical resistance and a low thermal expansion coefficient making it particularly suitable for its use as laboratory glassware. For the windows of these cells we use a borosilicate glass manufactured using the float process. An empty cell made from this material has a transmission of greater than 80 % at a spectral range of between 330 nm and 2500 nm.