The absorbance accuracy of the filters are measured at up to six different values using neutral density filters with calibration values traceable to the National Physical Laboratory (NPL), certificate reference no1545. The measurements were made at a wavelength of 510nm in the absorbance. Absorbance calibration within 0.005A or 1%.
The wavelength accuracy of the filters are measured against 11 wavelength using Holmium and Didymium filters traceable to National Physical Laboratory (NPL) certificate C1474 and C1476. Wavelength calibration within ± 0.5nm, level of uncertainly ± 0.3nm.
|
Wavelength Calibration Filters
Holmium
and Didymium
filters
are calibrated to the required standards. Filters are supplied
mounted in adonised black holders to fit standard 1cm
cuvette holders usually supplied with most spectrophotometers.
Unmounted filters can also be supplied without any certification
see stock sizes
The mounted filters are supplied in a box (up to 4 filters per box), labelled with the optical density with a certificate at the stated values. Blank holders can also be purchased which can be used as a balancing filter. |
 |
For more details on other neutral density filters please see our stock or custom range of nd filters.
| You can purchase single filters or make up your own sets, the mounted filters are available in the nominal density’s/transmissions over (400-1100nm) | |||
|
 |
||
