Neutral Density Filters

Purpose

These references can be used to qualify the absorbance accuracy and linearity of near-infrared spectrophotometers with a spectral bandwidth of 6.5 nm or less, over the wavelength range 800 nm - 3200 nm.

Description and Discussion

Glass filters mounted ‘stress free’ in an anodised aluminiumholder. The use of Schott NG-type glasses is well established for the validation of the absorbance scale and linearity of spectrophotometers in the near-infrared region.

The spectrum of these filters is relatively flat over most of the range of calibration, but with significant deviation above 2700 n

Calibration values (in % Transmission and Absorbance) are certified at 1100, 1700, 2210, 2500 and 2850 nm. Three filters are available, designated, R1 R3 and I1. Approximate values are:

Wavelength	1100 nm		1700 nm		2210 nm		2500 nm		2850 nm
Scale	%T	A	%T	A	%T	A	%T	A	%T	A
R1	20	0.70	40	0.40	47	0.32	49	0.31	2	1.83
R3	25	0.59	46	0.34	53	0.28	55	0.26	3	1.54
I1	33	0.48	53	0.28	59	0.23	60	0.22	6	1.25

Typical spectra

Catalogue Number

1100 nm	1700 nm	2210 nm	2500 nm	2850 nm	Catalogue Number
%T	A	%T	A	%T	A	%T	A	%T	A
20	0.70	40	0.40	47	0.32	49	0.31	2	1.83	RM-R1
25	0.59	46	0.34	53	0.28	55	0.26	3	1.54	RM-R3
33	0.48	53	0.28	59	0.23	60	0.22	6	1.25	RM-I1
Set of all 3 filters as above	RM-R1R3I1

Product enquiry

Data sheet

Technique

NIR References

NIR Neutral Density Glass References

Purpose

Description and Discussion

Typical spectra

Catalogue Number

Product enquiry

Data sheet

In order to provide you with the best online experience this website uses cookies.

Cookie Policy

Technique

NIR References

NIR Neutral Density Glass References

Purpose