SSUV300 In vitro UVA testing of sunscreen products (COLIPA)
The SSUV300 performs the accurate measurement of UV transmittance through thin film sunscreen samples in strict accordance with the COLIPA guideline “Method for the In vitro Determination of UVA Protection Provided by Sunscreen products”.
There are a number of fundamental difficulties with this method that all require careful instrument design. Bentham has drawn on its extensive instrument design experience and applications knowledge to produce a turnkey solution that offers accurate and repeatable measurements.
Sunscreens are highly absorbing in the UV
The need to measure highly absorbing samples in the UV requires the system to have a large dynamic range. Therefore, high sctattered light rejection within the system is essential. The SSUV300 is based on the DTMc300 double monochromator which has excellent scattered light rejection proven in many demanding UV applications. Absorption levels over 6 decades (down to 6 O.D.) can be measured with confidence.
Sunscreen products fluoresce
Sunscreen products typically exhibit strong fluorescent effects which need to be suppressed during a measurement.
The SSUV300 minimises fluorescent effects in a most elegant way. The sample is placed in between the two halves of the double monochromator.
This eliminates the fluorescence effects more effectively than conventional filter techniques whilst retaining the full scattered light rejection performance of the double monochromator.
Additionally, because the two halves can be independently controlled, it is possible to fully investigate fluorescence effects by producing both excitation and emission spectra of any sample.
Measurement result courtesy of Institut Dr Schrader, Holzminden, Germany