Glasses for protecting eyes from injurious radiations[3rd ed.] . ivein its absorption at in, but beyond 3/* the transmission is as highas in uncolored glass. Curve B, Fig. 4, gives the transmission of Corning G 5 CAD(shade 6; thickness, mm). The maximum transmission isabout 5 per cent in the visible, and the infra-red absorption is more Glasses for Protecting the Eyes ii effective than obtains in curve A. Neither of these types of glassesare as effective as the blue-green glass G 124 J, thickness, mm(C, Fig. 4) for obstructing the infra-red, although they are betteradapted for absorbi
Glasses for protecting eyes from injurious radiations[3rd ed.] . ivein its absorption at in, but beyond 3/* the transmission is as highas in uncolored glass. Curve B, Fig. 4, gives the transmission of Corning G 5 CAD(shade 6; thickness, mm). The maximum transmission isabout 5 per cent in the visible, and the infra-red absorption is more Glasses for Protecting the Eyes ii effective than obtains in curve A. Neither of these types of glassesare as effective as the blue-green glass G 124 J, thickness, mm(C, Fig. 4) for obstructing the infra-red, although they are betteradapted for absorbing the visible rays. A further illustration of this type of glass is shown by D, Fig. 4,which gives the transmission of a Noviweld goggle. This glasstransmitted about per cent at the maximum in the visible(thickness, 2 mm). On the other hand, the coloring matter is butlittle more effective than Corning G 124 HL for obstructing theinfra-red. The latter transmits about 38 per cent of the infra-redradiations from a furnace heated to 10500 C. (See F, Fig. 12.). yU. Fig. 4 Corning glasses: A,G 124 HL, shade 3 (t= mm); B,G 5 CAD, shade 6(t= mm); D,G 124 HX,shade6 (t= mm). C, blue-green glass, G 124 J (t= mm) BLACK GLASSES Black glasses are commonly used for absorbing the visible andthe ultra-violet rays. Very dense black glass obstructs the infra-red quite as well as some of the newer, more expensive coloredglasses just described. Curve D in Fig. 2 gives the transmission 12of a sample of Schotts black glass ( Rauchglass 444 III; thick-ness, mm), sometimes used in optical pyrometers. The trans-mission in the visible spectrum is quite uniform and it amounts toabout per cent. In the infra-red the transmission is as lowas the colored glasses just described. In fact, the sample illus-trated in Fig. 2 transmitted but little beyond 3/*, although a lighter 32 Coblentz, Publication No. 97, Carnegie Institution of Washington, 1908. E2 Technologic Papers of the
Size: 2018px × 1238px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorcoblentz, bookcentury1900, bookdecade1910, bookyear1919
