Case of Glass Standards, National Bureau of Standards

Can anyone tell me what these glass standards were used for? (Frankly, I'm not even sure what they are, exactly.)

So we have a little black box with 6 pieces of glass, 5 square, 1 round. (white spots on the glass are from ceiling lights...sorry.) The thickness varies - the bright red/orange (lower left) is the thinnest and they graduate up in thickness. Each one has a tiny number on it, the red/orange one being NSB 2101 29, and the 4 numbers in the center graduate upward (2101, 2102, etc). There's also a card with information about the thickness in MM, then Cap X, Cap Y, Cap Z, and then X and Y.

The round glass may or may not be part of the original set. It isn't numbered but does have an old Corning label that says Diaymium 5.06MM No. 512.

If anyone can tell me what standards these would have been used for or any other info, I'd appreciate it!

Thanks so much!

 

Looks like samples of sunglasses lenses, not sure. Could also be for old photography or the lenses even used for digital photography. The samples are very neat and the box is nice too!

 

It took a little time to get a reply, but the Corning Museum was delightfully helpful when I sent an inquiry. If I remember correctly, they actually have a communication choice for 'question about something I own' (or to that effect). If Antiquers fails you...

 

Didymium, I think. Safety glass. I think those are all varying safety glass samples, against strong light and so forth, with varying capacities for light blocking and diffusion.

 

LA set of five specially selected colored-glass filters to identify variables of malfunction
of photoelectric recording spectrophotometers equipped with tristimulus integrators have
been standardized on a number of spectrophotometers corrected for all known errors (wavelength,
zero, 100 percent, slit-width, inertia, back-reflectance, and stray-energy) J To these
standardized spectrophotometric data definite amounts of these errors were deliberately
introduced and converted to tristimulus values and chromaticity coordinates of the International
Commission of Illumination system of colorimetry for Sources A, B, and C. Similar
reductions show the effects of slit widths of 1, 5, 10, and 15 millimicrons (HIM) on computed
results both by the selected-ordinate method of 10, 30, and 100 ordinates, and by the
weighted-ordinate methods of 1-, 5-, 10-, and 15-mju intervals. Duplicate sets of these
glasses have been evaluated by visual comparison with this set of master standards, and are
available as part of the Standard Materials Program of the National Bureau of Standards.
By comparing the certified values of luminous transmittance and chromaticity coordinates
for a set of these glasses with the values obtained on a particular integrator-spectrophotometer
combination, the type and extent of instrumental errors may be evaluated.

Materials. Two hundred 2 X 2-in. polished squares
of each of five types of glass, each group of 200
squares being from the same melt, were purchased
from Corning Glass Works. Our designations for
the five types of glass, the Corning designation, and
thickness are as follows:
2101, Selenium orange red, Corning 3480, 2.6 mm.
2102, Signal yellow, Corning 3307, 2.6 mm.
2103, Sextant green, Corning 4010, 4.4 mm.
2104, Cobalt blue, Corning 5551, 2.6 mm.
2105, Selective neutral, special glass developed by
Corning for this project, Corning 5045, 2.9 mm.

https://www.google.com/url?sa=t&rct....N03.A01.pdf&usg=AOvVaw3bQVRHagpKbPYwOfO9bQJx

 

Googling 'glass standards set' produces results that are mostly barely comprehensible to me, but overall I understand that these sets are used in the calibration of gizmos that analyze the molecular composition of things using light to do it. Here's a letter published in a technical journal that you don't have to fully understand to get the gist. The thing most like it I have encountered in my own experience has been jewelers at trade shows who have a set of metal bars guaranteed to be 14K gold, or 925 silver, etc., to check on the accuracy of any electronic metal analysis machine they might be considering buying or to test out the competition.

See I have been out-teched while typing.

 

"In the February 1941 meeting of the optical Society of America, it was announced that Corning 5120 didymium glass filters were available from NBS for calibrating the wavelength scale of spectrophotometers " Spectrophotometers use light absorbance to measure concentrations of solutions...50+ years of teaching science doesn't normally come in handy in the antique field

 

Bet now you know more than you ever wanted.

 

WOW! Thanks!
I must say I now know more than I did before! Now to find a buyer who's just itching to calibrate the wavelength scales of spectrophotometers.

 

LOL!!