Certified Reference Materials for Checking the Wavelength Accuracy
The ideal standard to measure wavelength accuracy has very narrow, well defined peaks at a series of wavelengths throughout the UV and visible range. There are several standards suitable for wavelength calibration, which are described in different regulations (e.g. USP, Ph. Eur.).
In accordance with regulations
The following table shows an overview of the filters offered by Hellma and their accordance with the most important regulations:
> open table
When measuring the wavelength accuracy, the light beam of the spectrophotometer of specific wavelenghts will be weakened stronger by the filter used (peaks). The ideal standard to measure wavelength accuracy has very narrow, well defined peaks at a series of wavelengths throughout the UV and VIS range.
For common wavelength accuracy standards, because the peaks are not ideally symmetrical, changes in the slit width of the instrument will slightly affect the measured position of the peaks. Because of the narrow bands of the peaks the heights of the measured maxima will vary with a change of the slit width. Therefore standards for checking the wavelength accuracy are in general not suited for checking the photometric accuracy.