Calibration Standard, Holmium Oxide Glass
For checking wavelength calibration of spectrophotometers
As suggested by Dr. J.M. Vandenbelt of Parke-Davis Laboratories in article “Holmium Filter for Checking the Wavelength Scale of Recording Spectrophotometers”, Vol. 51, p. 802 (1961)
Use of glass filters for spectrophotometer wavelength calibration should be considered auxiliary to, rather than a substitute for, the emission spectra of the mercury vapor lamp
8470F10 consists of 8470F18 Filter and a Holder
Fits spectrophotometers that are equipped to take standard 10 mm cuvettes
8470F18 Filter is Corning No. 3130 glass, cut to 10 x 24.5 mm; is UV-transmitting and has several sharp absorption bands near 241, 280, 288 and 360 nm
8470F10 furnished with representative spectral transmittance curve for holmium oxide filter
Hinged back is spring-loaded to hold filter in place. Filters of other types, 10 x 24.5 mm and up to 4.5 mm thick, can be substituted in the holder. Filters easily removable for cleaning.
Calibration Filter, Didymium Glass
For use in a Filter Holder
Size 10 x 24.5 mm
Of Corning 5120 Glass
Has many sharp peaks for checking wavelength in visible range. Representative spectral curve furnished with filter.
Calibration Filter, Didymium Glass, Round
Usable with Spectronic 20, Spectronic 20D or Sequoia-Turner Models 330, 340, 350 and 380 Spectrophotometers
For checking calibration in visible range and meter performance
See R.N. Rand, “Practical Spectrophotometric Standards,” Optical Chemistry, 15, 839-863 (1969)
Consisting of a Corning No. 1-60 didymium glass filter mounted in end of phenolic plastic holder, approximately 13 mm diameter x 100 mm long. Window in opposite end of holder provides unobstructed air path for light beam when holder is inverted for setting meter reading at 100% transmittance. Complete with directions for use, including spectral transmission curve for filter. Temperature change can cause slight shift in transmission curve. Fits holders 8420Q18 and 8425D50.