This Reference Material can be used to qualify the Absorbance scale, in the ultra-violet and visible region of the spectrum (250 nm to 850 nm) of spectrophotometers with spectral bandwidths not exceeding 10 nm.
These filters are equivalent to NIST SRM 2031c. A metallic coating is deposited on to a fused silica plate at a thickness that determines the transmission characteristics of the filter. The metallic surface is overlaid by an optically bonded cover plate, to protect it from oxidation, contamination, or physical degradation.
Note that SRM 2031a and SRM 2031b are no longer available from NIST, and were replaced by SRM 2031c. SRM 2031b used an evaporated silicon dioxide protective overcoating rather than a protective cover plate in the construction. We consider the bonded cover plate to be more durable than the overcoating method and have therefore retained the earlier design as per SRM 2031a and SRM 2031c. The filters are mounted in stress-free black-anodized aluminium alloy holders, with front and rear sliding covers that protect the filters when not in use. All individual references and sets are supplied with an empty filter holder for use as a measurement reference.
The spectrum of these filters is essentially flat from 250 nm to 850 nm.
This Reference Material can be used to qualify the Absorbance scale, in the ultra-violet and visible region of the spectrum (250 nm to 850 nm) of spectrophotometers with spectral bandwidths not exceeding 10 nm.
These filters are equivalent to NIST SRM 2031c. A metallic coating is deposited on to a fused silica plate at a thickness that determines the transmission characteristics of the filter. The metallic surface is overlaid by an optically bonded cover plate, to protect it from oxidation, contamination, or physical degradation.
Note that SRM 2031a and SRM 2031b are no longer available from NIST, and were replaced by SRM 2031c. SRM 2031b used an evaporated silicon dioxide protective overcoating rather than a protective cover plate in the construction. We consider the bonded cover plate to be more durable than the overcoating method and have therefore retained the earlier design as per SRM 2031a and SRM 2031c. The filters are mounted in stress-free black-anodized aluminium alloy holders, with front and rear sliding covers that protect the filters when not in use. All individual references and sets are supplied with an empty filter holder for use as a measurement reference.
The spectrum of these filters is essentially flat from 250 nm to 850 nm.
