Document daDkgD15LjOLeNLjwp8NOYwn9

19--Personal Protective Equipment TABLE 19-A TRANSMITTANCES AND TOLERANCES IN TRANSMITTANCE OF VARIOUS SHADES OF FILTER LENSES Shade Ato Optical Density Min Std Max Luminous Transmittance Max Std Min Maximum Infrared Transmit* lance Maximum Spectral Transmittance in the Ultraviolet and Violet for Four Wavelengths (millimicrons) 313 334 365 405 1 5 017 1 7 026 20 036 25 054 30 0 75 0 214 0 300 0 429 0643 0 857 per cent per cent per cent per cent per cent per cent per cent per cent 026 036 054 0 75 1 07 67 55 43 29 180 61 1 501 37 3 22 8 139 55 43 29 18 0 850 25 20 15 12 90 02 02 02 02 02 08 25 65 07 20 50 05 14 35 03 5 15 02 05 6 40 1 07 50 1 50 60 1 93 70 236 80 2 79 1 286 1 714 2 143 2 571 3 000 1 50 1 93 2 36 279 3 21 8 50 316 1 18 044 0164 518 1 93 0 72 0 27 0100 3 16 1 18 044 0 164 0 061 50 02 02 05 10 25 02 02 02 05 1 5 01 01 01 05 1 3 01 01 01 05 1 0 01 01 01 05 90 3 21 100 364 11 0 4 07 120 4 50 130 4 93 140 5 36 3 429 3 857 4 286 4 714 5 143 5 571 364 4 07 450 4 93 5 36 5 79 0061 0023 0 0085 0 0032 00012 0 0004 0 037 0 0139 0 0052 0 0019 0 00072 0 00027 0 023 0 0085 0 0032 00012 0 00044 0 00016 08 06 05 05 04 03 01 01 005 005 005 005 01 01 0 05 0 05 0 05 0 05 01 01 0 05 005 0 05 0 05 05 05 01 01 01 01 NOTE The values given apply to class I filter glass For class II filter lenses, the transmittances and tolerances are the same with the additional requirement that the transmittance of 589 3 millimicrons shall not exceed 15 per cent of the luminous transmittance Some of the headings in this table have been changed to conform with N8S Letter Circular LC857 Spectral-Transmissive Properties and Use of Eye-Protective Classes Reprinted from National Bureau of Standards Circular 471, 1948 DICHROIC coated glass plate (coating faces chemicals may be provided in a variety of ways, depending upon the hazard Good protection is given by a hood made of chemi cal-resistant material with a glass or plasbc window (Fig 19-20) In all cases, there should be a secure joint between the window and the hood materials Hoods are extremely hot to wear, and can be obtained with air lines for the wearer's comfort When a hood is so supplied, the wearer should have a harness or belt like that on an air line respirator (see Fig 19-30 and -31) for support of the hose A device based on a vortex principle has been developed to provide temperature-conditioned air (See Fig 19-36) If protection is necessary only from limited direct splashes, the wearer can don a face 486 <Fic 19-22 --Diagram shows how "antilaser eyeshield" deflects laser beam