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Potassium dichromate liquid filter

Potassium dichromate dissolved in perchloric acid is a highly suitable method to check the photometric accuracy of the spectrometer. Potassium dichromate gives a spectral scan containing characteristic peak maxima at 257 nm and 350 nm and minima at 235 nm and 313 nm. The plateau in the spectrum at 430 nm is used to determine the fotometric accuracy in the visible spectral range. Hellma Analytics buys the reference material for the filters directly from NIST (SRM® 935a „Potassium Dichromate“). The filter solutions are produced striclty according to the guidelines of NIST, filled up under controlled circumstances, and immediately melted off, and sealed airtight.

Please note:

The individually measured absorbance values are free from any systematic errors in the preparation of the solution and in the light path. The measured data of the reference filters UV14 (perchloric acid measured against air) is separately shown on the DAkkS calibration certificate (german accreditation body). To check the linearity of the absorption, perform the measurement with the potassium dichromate filter in different concentrations. Enter the measured absorption values for each filter and each wavelength in a diagram against the measured values on the DAkkS calibration certificate.

Absorbance table of UV20 - UV0200

Filter type (Art.-No.)Average absorptions at wavelength
UV20 (667020)0,250,290,100,22
UV40 (667040)0,500,570,200,43
UV60 (667060)0,750,860,300,65
UV80 (667080)1,001,160,400,86
UV0100 (6670100)1,251,450,501,07
UV0120 (6670120)1,501,750,601,28
UV0140 (6670140)1,752,050,701,50
UV0160 (6670160)2,002,350,801,70
UV0180 (6670180)2,252,650,901,90
UV0200 (6670200)2,502,951,002,10

E_ Kaliumdichromat- Flüssigfilter Typical spectrum of a 0.006 % potassium dichromate solution
kalibrierstandards1_2a2.gif Typical spectrum of a 0.06 % potassium dichromate solution

Article-no.667020, 667040, 667060, 667080, 6670100, 6670120, 6670140, 6670160, 6670180, 6670200, 667600, 667014 (reference filter)
ApplicationTo check the photometric accuracy in UV range (235 nm until 350 nm) and Vis range (measuring wavelength 430 nm)
MaterialPotassium dichromate dissolved in perchloric acid, sealed in Hellma precision cells made from quartz SUPRASIL®

UV20: 20 mg/l Potassium dichromate in HClO4 (0,1 - 0,3 Abs), according to USP

UV40: 40 mg/l Potassium dichromate in HClO4 (0,2 - 0,6 Abs), according to USP
UV60: 60 mg/l Potassium dichromate in HClO4 (0,3 - 0,9 Abs), according to USP and Ph. Eur.
UV80: 80 mg/l Potassium dichromate in HClO4 (0,4 - 1,2 Abs), according to USP
UV0100: 100 mg/l Potassium dichromate in HClO4 (0,5 - 1,45 Abs), according to USP
UV0120: 120 mg/l Potassium dichromate in HClO4 (0,6 - 1,7 Abs), according to USP
UV0140: 140 mg/l Potassium dichromate in HClO4 (0,7 - 2,0 Abs), according to USP
UV0160: 160 mg/l Potassium dichromate in HClO4 (0,8 - 2,3 Abs), according to USP
UV0180: 180 mg/l Potassium dichromate in HClO4 (0,9 - 2,6 Abs), according to USP
UV0200: 200 mg/l Potassium dichromate in HClO4 (1,0 - 3,0 Abs), according to USP
UV600: 600 mg/l Potassium dichromate in HClO4 (1,0 Abs), according to Ph. Eur.
UV14: perchloric acid (HClO4), reference filter
Standard certificationAt UV20 until UV0200 wavelength: 235; 257; 313; 350 nm
At UV600 wavelength: 430 nm
Slit width: 2 nm
with DAkkS calibration certificate
Possible certificationsWavelength: fixed
Slit width: all until 2 nm

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