Starna Scientific offers an extensive range of Certified Reference Materials for qualifying the wavelength scale of ultraviolet and visible spectrophotometers, with an overall wavelength coverage from 190 nm to 1945 nm. Rare earth oxide solutions are accepted by most Pharmacopoeias for wavelength qualification in the ultraviolet region, and Starna’s unique range of these materials gives the most extensive wavelength coverage available from any supplier.


Holmium Oxide Solution (240 - 650 nm)

The most widely used liquid wavelength reference, recognised by most Pharmacopoeias and standardisation bodies; gives a spectral scan containing 14 characteristic and well-defined peaks covering wavelengths from 240 nm to 650 nm. Included in Starna’s instrument qualification kits.

Approximate peak wavelength values (in nm) are: 241, 250, 278, 288, 334, 346, 361, 385, 417, 451, 468, 485, 537, 641

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Cerium oxide solution  (200 -270 nm)

Now recommended by pharmacopoeias for qualifying spectrophotometers in the far UV. Included in Starna’s instrument qualification kits.

Approximate peak wavelength values (in nm) are: 201, 211, 223, 240, 254  

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Didymium Oxide Solution (290 – 870 nm)

The spectrum of didymium in perchloric acid contains 14 peaks that can be certified for wavelength, covering the range from 290 nm to 870 nm. This reference is useful for its NIR coverage.

Approximate peak wavelength values (in nm) are: 298, 329, 354, 444, 469, 482, 512, 522, 576, 732, 740, 794,799, 864

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Combined Holmium/Didymium Solution (240 – 795 nm)

This reference has useful peaks evenly distributed over its whole wavelength range, from 240 to 795 nm.
14 peaks are certified, with nominal values: 241, 287, 361, 416, 444, 482, 485, 522, 537, 575, 641, 732, 740 and 794 nm.

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Holmium Oxide Glass (240 - 640 nm)

This solid material is physically more robust than Its liquid equivalent and can therefore be used in a more demanding environment, so is useful as a routine wavelength calibration check. It is, however, not accepted by all Pharmacopoeias for wavelength qualification

Approximate peak wavelength values (in nm) are: 242, 279, 288, 334, 361, 419, 446, 454, 460, 537, 638

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Combined Holmium/Neutral Density Glass

With this combined filter, the holmium spectrum is superimposed on an approximately constant 1A background, useful as an absorbance accuracy check. 7 peak wavelengths are certified at nominal values of 361, 419, 446, 454, 460, 537 and 638 nm.

Absorbance values, nominally 1A, are certified at wavelengths between the holmium peaks at 431, 516, 557, 594 and 623 nm

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Didymium Glass Filter (430 – 890 nm)

The didymium (neodymium & praseodymium) Glass  filter  produces characteristic peaks in the  visible region of the spectrum, with 11 well-defined peaks  from  430 nm to 890 nm.

Approximate peak wavelength values (in nm) are: 431, 473, 513, 529, 573, 585, 685, 741, 749, 807, 879.

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Combined Didymium/Neutral Density Glass

With this combined filter, the holmium spectrum is superimposed on an approximately constant 1A background, useful as an absorbance accuracy check. 9 peak wavelengths are certified at nominal values of 473, 514, 530, 572, 586, 739, 748, 807 and 879 nm.

Absorbance values, nominally 1A, are certified at wavelengths between the didymium peaks, at 410, 455, 550, 637 and 773 nm.

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Starna wide-range wavelength references  (335 – 1945 nm)

This exceptionally wide-range filter contains a mixture of rare earth oxides and provides 20 peaks for wavelength calibration between in the NIR. It is equivalent to NIST SRM 2065. Nominal peak wavelength values (in nm) are: 335, 345, 361, 375, 386, 402, 418, 485, 538, 583, 642, 748, 804, 976, 1076, 1151, 1222, 1366, 1469, 1945

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Deep UV Reference (190 - 230 nm)

This novel reference material is certified for wavelength qualification at nominal values of 191 nm, 209 nm and 226 nm. It is also certified for absorbance qualification at these wavelengths. Approximate absorbance values are 0.9 A, 0.3 A and 0.9 A respectively.

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Samarium Oxide Solution (230 – 560 nm)

Samarium perchlorate is a particularly useful reference material for checking the wavelength scale over the commonly  used region from 200 nm to 500 nm. 
Approximate peak wavelength values (in nm) are: 235, 279, 290, 305, 318, 332, 344, 362, 374, 391, 401, 415, 464, 479

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