Appendix A A-18 Equation 70-1.3: Calculating SZED (slant range) exposure distance 𝑆𝑍𝐸𝐷𝑆𝑅 = 32.8𝑚𝑟𝑎𝑑 × √12732 × 𝑊𝑉𝐶𝑃
Equation Term Explanation SZEDSR SZED slant range (feet)
32.8 Conversion factor used to convert centimeters into feet and radians into milliradians (0.0328 feet per centimeter) mrad Beam divergence (milliradians) 12,732 4/π (derived from the original ANSI equation) then divided by the SZED exposure level of 0.0001 W/cm2 in the denominator WVCP Visually corrected power (watts from cell 12c.)
CZED slant range: To calculate the CZED slant range (CZEDSR) distance, multiply the SZEDSR by 4.47. Enter the product in cell 14c (slant range column).
Equation 70-1.4: Calculating CZED (slant range) exposure distance 𝐶𝑍𝐸𝐷𝑆𝑅 = 𝑆𝑍𝐸𝐷𝑆𝑅 × 4.47 LFED slant range: To calculate the LFED slant range (LFEDSR) distance, multiply the SZEDSR by 44.7. Enter the product in cell 14d (slant range column).
Equation 70-1.5: Calculating LFED (slant range) exposure distance 𝐿𝐹𝐸𝐷𝑆𝑅 = 𝑆𝑍𝐸𝐷𝑆𝑅 × 44.7 A.16.4.1. Horizontal and Vertical Distance Calculations Using the calculated slant ranges, calculate the distances for the horizontal and vertical columns.
These distances assist FAA personnel in determining the distance along the ground and the altitudes that require protection. The equations use the cosine (cos) and sine (sin) functions and the minimum and maximum elevation angles entered in cells 13a and 13b, respectively.
NOTE: Because FAA requires (and formulas in this AC provide) the slant range in feet, the horizontal and vertical distances will also be in feet.
Appendix A A-19 A.16.4.2. Horizontal and Vertical Distances for NOHD Using the previously calculated NOHD slant range (NOHDSR) and the previously entered maximum and minimum elevation angles (cells 13a and 13b), use the following formulas to calculate the horizontal and vertical distances for the NOHD. To obtain the sine (sin) and cosine (cos) of the angles, use a scientific calculator or a table of sine and cosine values. Enter the calculated values in the appropriate columns of section 14a.
Equation 70-1.6: Calculating NOHD horizontal distance 𝑁𝑂𝐻𝐷 ℎ𝑜𝑟𝑖𝑧𝑜𝑛𝑡𝑎𝑙 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 = 𝑁𝑂𝐻𝐷𝑆𝑅 × 𝑐𝑜𝑠(𝑚𝑖𝑛𝑖𝑚𝑢𝑚 𝑒𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝑎𝑛𝑔𝑙𝑒) Equation 70-1.7: Calculating NOHD vertical distance 𝑁𝑂𝐻𝐷 𝑣𝑒𝑟𝑡𝑖𝑐𝑎𝑙 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 = 𝑁𝑂𝐻𝐷𝑆𝑅 × 𝑠𝑖𝑛(𝑚𝑎𝑥𝑚𝑖𝑢𝑚 𝑒𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝑎𝑛𝑔𝑙𝑒) NOHD vertical and horizontal distance calculation example What are the NOHD horizontal and vertical distances for the following laser?
Given:
NOHDSR: 1000 feet Minimum elevation angle: 15 degrees Maximum elevation angle: 45 degrees Solutions (rounded to the nearest foot):
𝑁𝑂𝐻𝐷 ℎ𝑜𝑟𝑖𝑧𝑜𝑛𝑡𝑎𝑙 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 = 1000 × 𝑐𝑜𝑠(15) = 1000 × 0.9659 = 𝟗𝟔𝟔 𝒇𝒕 𝑁𝑂𝐻𝐷 𝑣𝑒𝑟𝑡𝑖𝑐𝑎𝑙 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 = 1000 × 𝑠𝑖𝑛(45) = 1000 × 0.7071 = 𝟕𝟎𝟕 𝒇𝒕 A.16.4.3. Horizontal and Vertical Distances for SZED, CZED, and LFED Using the previously calculated slant ranges for the SZEDSR, CZEDSR, and LFEDSR and the previously entered minimum and maximum elevation angles (cells 13a and 13b); use the following formulas to calculate the horizontal and vertical distances for the SZED, CZED, and LFED.
To obtain the sine and cosine of the angles, use a scientific calculator or a table of sine and cosine values. Enter the calculated values in the appropriate columns of sections 14b, 14c, and 14d.
Equation 70-1.8: Calculating SZED horizontal distance 𝑆𝑍𝐸𝐷 ℎ𝑜𝑟𝑖𝑧𝑜𝑛𝑡𝑎𝑙 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 = 𝑆𝑍𝐸𝐷𝑆𝑅 × cos(𝑚𝑖𝑛𝑖𝑚𝑢𝑚 𝑒𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝑎𝑛𝑔𝑙𝑒)
Appendix A A-20 Equation 70-1.9: Calculating SZED vertical distance 𝑆𝑍𝐸𝐷 𝑣𝑒𝑟𝑡𝑖𝑐𝑎𝑙 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 = 𝑆𝑍𝐸𝐷𝑆𝑅 × sin(𝑚𝑎𝑥𝑖𝑚𝑢𝑚 𝑒𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝑎𝑛𝑔𝑙𝑒) Equation 70-1.10: Calculating CZED horizontal distance 𝐶𝑍𝐸𝐷 ℎ𝑜𝑟𝑖𝑧𝑜𝑛𝑡𝑎𝑙 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 = 𝐶𝑍𝐸𝐷𝑆𝑅 × cos(𝑚𝑖𝑛𝑖𝑚𝑢𝑚 𝑒𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝑎𝑛𝑔𝑙𝑒) Equation 70-1.11: Calculating CZED vertical distance 𝐶𝑍𝐸𝐷 𝑣𝑒𝑟𝑡𝑖𝑐𝑎𝑙 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 = 𝐶𝑍𝐸𝐷𝑆𝑅 × sin(𝑚𝑎𝑥𝑖𝑚𝑢𝑚 𝑒𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝑎𝑛𝑔𝑙𝑒) Equation 70-1.12: Calculating LFED horizontal distance 𝐿𝐹𝐸𝐷 ℎ𝑜𝑟𝑖𝑧𝑜𝑛𝑡𝑎𝑙 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 = 𝐿𝐹𝐸𝐷𝑆𝑅 × cos(𝑚𝑖𝑛𝑖𝑚𝑢𝑚 𝑒𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝑎𝑛𝑔𝑙𝑒) Equation 70-1.13: Calculating LFED vertical distance 𝐿𝐹𝐸𝐷 𝑣𝑒𝑟𝑡𝑖𝑐𝑎𝑙 𝑑𝑖𝑠𝑡𝑎𝑛𝑐𝑒 = 𝐿𝐹𝐸𝐷𝑆𝑅 × sin(𝑚𝑎𝑥𝑖𝑚𝑢𝑚 𝑒𝑙𝑒𝑣𝑎𝑡𝑖𝑜𝑛 𝑎𝑛𝑔𝑙𝑒) A.17. Section 15. Calculation Method Select the method used to perform the calculations. If using commercial software, enter the software product name and the version. If using a method other than commercial software (e.g., spreadsheet or calculator), describe the method in this section.
NOTE: Software may use slightly different MPE values than FAA specifies. For example, some software uses 2.55 mW/cm2 as the MPE for visible-light wavelengths from 400 nm to 700 nm, while FAA uses 2.6 mW/cm2. This can create a small difference of a few percent in determining hazard distances. For FAA protection purposes, such small differences are acceptable.
i Source note: ANSI Z136.1 is the source of the equations derived above, re-expressed to a simpler form as follows.
• Beam divergence (mrad): Used milliradians, making the first ANSI fraction 1,000/mrad instead of 1/mrad.
• Radical/square root sign: Used instead of raising to a power of 0.5.
• Under the radical, reduced the expression of 4/π to 1.2732. For equations that use MPE in milliwatts, multiplied 1.2732 by
0.001 as the original ANSI equation uses watts.
• Did not use beam diameter (a2) under the radical since its contribution to the overall slant range distance is negligible. For beams with diameters at the output aperture more than 1 cm, do not use the equations but instead refer to ANSI Z136, Appendix B. to determine protection distances NOHD and (if visible) SZED, CZED, and LFED.
• Distance (centimeters and feet): ANSI expresses the results of its equations in centimeters whereas FAA requires expression in feet.
o Equations use a conversion factor of 0.0328 (1 cm = 0.0328 ft).
o There are now two numeric constants: 1,000 (from the milliradians fraction) and 0.0328.
o The product of the two constants is a single constant (32.8) to provide results in feet.
o Note: For results in centimeters, use “1,000” as the constant. For results in meters, use “10.”
• SZED, CZED, and LFED equations o Found by using the SZED exposure level of 0.0001 W/cm2 as the denominator under the radical.
o The quotient of dividing 1.2732 in the numerator by 0.0001 in the denominator results in a constant of 12,732.
o There is a fixed relationship between the three distances; the CZED is always 4.47 times the SZED, and the LFED is always 44.7 times the SZED.
Appendix B B-1 Appendix B. Tables and Examples B.1. Maximum Permissible Exposure (MPE) Limits Use Tables 1 and 2ii along with any associated calculations to determine MPE. For any value (wavelength or exposure duration) that falls exactly on a high or low end of a range within the tables, use the more conservative (smaller) MPE. For repetitively pulsed lasers, the MPE is determined from the more restrictive MPE considering Table 1 for a single pulse and Table 2 for the average power.
Table 1 – Single Pulse Laser MPE Limits Wavelength (nm) Pulse Width t (seconds [s]) MPE Visible 400 to 700 1 ns to 5 s 0.2 J/cm2 5 s to 0.25 s 1.8 × t 0.75 mJ/cm2 Infrared 700 to 1050 1 ns to 5 s 0.2 × CA J/cm2 5 s to 0.25 s 1.8 × CA × t 0.75 mJ/cm2 1050 to 1320 1 ns to 13 s 2.0 × CC J/cm2 13 s to 0.25 s 9.0 × CC × t 0.75 mJ/cm2 1400 to 1500 1 ns to 1 ms 0.3 J/cm2 1 ms to 0.25 s (0.56 × t 0.25 + 0.2) J/cm2 1500 to 1800 1 ns to 0.25 s 1.0 J/cm2 1800 to 2600 1 ns to 1 ms 0.1 J/cm2 1 ms to 0.25 s 0.56 × t 0.25 J/cm2 2600 to 10000 1 ns to 0.1 s 10.0 mJ/cm2
0.1 s to 0.25 s 0.56 × t 0.25 J/cm2 Table notes
• For wavelengths or a pulse width not included in the table, refer to ANSI Z136.1.
• For clarity, FAA used metric prefixes (symbols) in place of scientific notation.
o m represents milli or 1 × 10-3 or 0.001, example 1 ms = 1×10-3 s.
o represents micro or 1 × 10-6 or 0.000001, example 1 s = 1×10-6 s.
o n represents nano or 1 × 10-9 or 0.000000001, example 1 ns = 1×10-9 s.
Appendix B B-2
• Correction factors CA and CC derived from ANSI Z 136.1. CA is a correction factor that increases the MPE in the near-infrared region (700 nm to 1400 nm), based on reduced absorption properties of the skin and eyes. CC is a correction factor that increases the MPE for ocular exposure based on pre-retinal absorption of radiant energy in the spectral region (1150 nm to 1400 nm).
• t: Pulse duration in seconds MPE CA correction factor For lasers with a wavelength of 700 to 1050 nm, use the following equation:
𝐶A = 100.002(𝑤𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ−700) Example 1
• Laser wavelength: 850 nm
• 𝐶A = 100.002(850−700) = 100.002(150) = 100.3 = 1.995 Example 2
• Laser wavelength: 933 nm
• 𝐶A = 100.002(933−700) = 100.002(233) = 100.466 = 2.924 MPE CC correction factor
• For lasers with a wavelength of 1050 nm to 1150 nm, use a CC of 1.0.
• For lasers with a wavelength of 1150 nm to 1200 nm, use the following equation:
• 𝐶C = 100.018(𝑤𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ−1150)
• For lasers with a wavelength of 1200 nm to 1320 nm, use the following equation:
• 𝐶C = 8.0 + 100.04(𝑤𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ−1250)
• For lasers with a wavelength of 1320 nm to 1400 nm, refer to ANSI Z136.1.
Example 3
• Laser wavelength: 1175 nm
• 𝐶C = 100.018(1175−1150) = 100.018(25) = 100.45 = 2.8
Appendix B B-3 Table 2 – Continuous Wave Laser MPE Limits (0.25 s Maximum Exposure Duration) Wavelength (nm) MPE (mW/cm2) Ultraviolet 180 to 400 Reference ANSI Z136.1 Visible 400 to 700 2.6 Infrared 700 to 1050 2.6 × CA 1050 to 1150 12.75 1150 to 1320 12.75 × CC 1320 to 1400 Reference ANSI Z136.1 1400 to 1500 2384 1500 to 1800 4000 1800 to 10000 1584 Table notes
• See Table 1 for CA and CC correction factors.
• Values are for selected wavelengths assuming unintentional viewing.6 Example 1
• Laser wavelength: Visible
• MPE: 2.6 mW/cm2
6 An unintentional laser exposure to the eye of a person in an aircraft is expected to last no more than 0.25 seconds based on various factors including the human aversion response (for visible wavelengths) and the natural relative motion between the beam and a moving aircraft related to wind and other stabilization factors. If the potential exposure may last for an increased duration or a proponent desires to complete a more precise analysis (e.g., wavelengths from 1050 nm to 1400 nm), refer to the ANSI Z136 standards for additional analysis techniques. Document and include the standards’ MPE exposure limits and calculations with the submission.
Appendix B B-4 Example 2
• Laser wavelength: 850 nm
• 𝐶A = 100.002(𝑤𝑎𝑣𝑒𝑙𝑒𝑛𝑔𝑡ℎ−700) = 100.002(850−700) = 100.002(150) = 100.3 = 1.995
• 2.6 × 𝐶A = 2.6 × 1.995 = 5.187 mW/cm2 B.2. Visual Correction Factors To find the Visually Corrected Power (WVCP) for a specified wavelength, multiply the Precorrected Power (PCP) by the VCF for the laser’s wavelength (from the table below).
Table 3 – Visual Correction Factor (VCF) for Visible Lasers (400 nm to 700 nm)iii Wavelength (nm) VCF Wavelength (nm) VCF 400 0.0004 495 0.2653 405 0.0008 500 0.3226 410 0.0012 505 0.4126 415 0.0026 510 0.5025 420 0.0040 515 0.6059 425 0.0078 520 0.7092 430 0.0116 525 0.7857 435 0.0173 530 0.8621 440 0.0230 535 0.9073 445 0.0305 540 0.9524 450 0.0380 545 0.9713 455 0.0490 550 0.9901 460 0.0599 555 1.0 (VCF = 1) 465 0.0754 560 0.9901 470 0.0909 565 0.9713 475 0.1150 570 0.9524 480 0.1391 575 0.9110 485 0.1735 580 0.8696 490 0.2079 585 0.8136
Appendix B B-5 Table 3 – VCF for Visible Lasers (Continued) Wavelength (nm) VCF Wavelength (nm) VCF 590 0.7576 650 0.1070 595 0.6953 655 0.0840 600 0.6329 660 0.0610 605 0.5677 665 0.0466 610 0.5025 670 0.0321 615 0.4421 675 0.0246 620 0.3817 680 0.0170 625 0.3235 685 0.0126 630 0.2653 690 0.0082 635 0.2202 695 0.0062 640 0.1751 700 0.0041 645 0.1411 — — If the laser’s wavelength falls between two table entries, use one of the two methods below to find the VCF.
• Conservative approach: Use the more conservative (larger) of the two given values from the table.
• Use laser safety software: If using software to calculate the VCF for a wavelength, submit a screenshot or printout showing the entered wavelength and the software’s resulting VCF value.
Appendix B B-6 Visually Corrected Power (WVCP) examples Example 1: A frequency-doubled YAG laser emits 10 watts of 532 nm continuous wave light.
From the table, 532 nm is between 530 and 535 nm. Use the more conservative (larger) VCF of 535 nm. Multiply the VCF of 0.9073 by 10 (watts) to obtain a Visually Corrected Power of
9.073 watts.
Example 2: An 18-watt continuous wave argon laser emits 10 watts at 514 nm light and 8 watts at 488 nm. Calculate each wavelength separately then add the resulting Visually Corrected Powers together to obtain the total Visually Corrected Power.
10 watts at 514 nm
• From the table, 514 nm is between 510 and 515 nm. Use the more conservative (larger) VCF of 515 nm.
• Multiply the VCF of 0.6059 by 10 (watts) to obtain the Visually Corrected Power of
6.059 watts.
8 watts at 488 nm
• From the table, 488 nm is between 485 and 490 nm. Use the more conservative (larger) VCF of 490 nm.
• Multiply the VCF of 0.2079 by 8 watts to obtain the Visually Corrected Power of
1.6632 watts.
Total visually corrected power
• Add the two VCPs together: 6.059 + 1.6632 = 7.722.
• The 18-watt laser in this example has a visually corrected power of only 7.722 watts.
Overall VCF
• Divide the total VCP by the PCP to obtain the overall VCF (7.722 / 18 = 0.4290).
• Enter “0.4290” as the VCF in cell 12c.
NOTE: These two examples show that the 10-watt YAG laser in Example 1 appears brighter to the eye (9.073 WVCP) than the 18-watt argon laser (7.722 WVCP) in Example 2.
Appendix B В.З. Multiple Visible-Light Projector Example?
Example data and calculations provided for multiple visible-light laser projectors Where: 1) All laser modes of operation are continuous wave, 2) Each projector emits one or more wavelengths, 3) All wavelengths are visible (400 nm to 700 nm),
4) All beams from the same projector have the same divergence, and 5) All projectors' beams aim at the same area to be protected (same configuration).
Row Data source Parameters and Calculations Projector 1 example Projector 2 example Projector 3 example Projector 4 example
LASER PARAMETERS Laser type Diode Diode Diode Argon-ion Laser hazard class (1, 2, 3R, 3B, or 4) Longest Total power (watts) 10 22 10 NOHD Proponent Beam divergence (miliradians) 0.5 0.5 Fill in cells NOHD CALCULATION 12a* and 14a using the Calculate, using data in rows 3 and 4. data and (Note: The equation is valid for the visible Nominal ocular hazard distance (NOHD) (feet) 2,296 3,406 4,592 * 3,247 calculations MPE of 2.6 mW/cm? for a 0.25 s exposure) 32.8/mrad x V490xW WAVELENGTH CALCULATIONS projector Proponent Wavelength 1 (nanometers) 633 630 445 514 Proponent Wavelength 1 power (watts) VCF of the two rows Table 3. If between rows, use the larger Wavelength 1 Visual Correction Factor (from Table 3) 0.2653 0.2653 0.0305 0.5852 Calculate, using data in rows 7 and 8 W1 power × W1 VCF Wavelength 1 Visually Corrected Power 1.0612 2.1224 0.305 1.1704 Proponent Wavelength 2 (nanometers) 532 520 (none - single 488 wavelengin Proponent Wavelength 2 power (watts) 12 Table 3 Wavelength 2 Visual Correction Factor (from Table 3) 0.9073 0.7092 n/a 0.1941 13 Calculate, using data in rows 11 and 12 Wavelength 2 Visually Corrected Power W2 power × W2 VCF 0.9073 2.8368 n/a 0.5823 14 Proponent Wavelength 3 (nanometers) 445 450 (none - single none - two wavelength) wavelengths) 15 Proponent Wavelength 3 power (watts) n/a n/a 16 Table 3 Wavelength 3 Visual Correction Factor (from Table 3) 0.0305 0.038 n/a n/a Wavelength 3 Visually Corrected Power 17 Calculate, using data in r rows 15 and 16 W3 power x W3 VCF 0.1525 0.38 n/a n/a 18 BE SURE TO ADD ROWS IF MORE THAN 3 WAVELENGTHS ... add more rows for any additional wavelengths Longest SZED Calculate, adding the VCPs previously alculated total or rows s, 15, 17) Total of all wavelengths' Visually Corrected Power (total will be Wyce) 2.12 5.34 0.31 1.75 Fill in cells 12a*, 14b 20 Calculate, using data in rows 19 and 3 Wycp / total power Total VCF for this laser 0.2121 0.2427 0.0305 0.3505 14c, and 14d using the PROTECTION DISTANCES CALCULATIONS data ano 21 Calculate, using data in rows 4 and 19 Sensitive Zone Exposure Distance (SZED) (feet) 32.8/mrad × V12732xWuCP 5,390 8,552 4,088 9,800 calculations for this 22 Calculate, using data in row 21 Critical Zone Exposure Distance (CZED) (feet) SZED × 4.47 24,094 38,227 18,273 43,804 projector 23 Calculate, using data in row 21 Laser-Free Exposure Distance (LFED) (feet) SZED × 44.7 240,935 382,268 182,730 438,040 i Source note: ANSI Z136.1 (2014) Tables 5 and 6.
ill Source note: The VCF (Cr) used in Table 3 is the Commission Internationale de l'Éclairage (CIE) normalized efficiency photopic visual function curve for a standard observer. The illuminance (Im), expressed in Im/cm?, is the measured irradiance multiplied by CF and 683. The effective irradiance is the actual (measured) irradiance multiplied by Cr. The effective irradiance (W/cm-2) multiplied by 683 1m/W-' is the illuminance (Im/cm-2).
7 Notes (* for NOHD and SZED) for this example.
• Record the data from the projectors with the longest NOHD and SZED then annotate (parentheses used here) which data Instance when the longest NOHD and longest SZED do not come from a single projector.
aligns to the projector with the longest SZED.
• For this example, complete 12a as follows:
Laser type: Diode (Argon-ion).
Laser hazard class: 4 (4).
Beam divergence: 0.5 (0.5).
Wavelength(s): 445 (514, 488).
List this attachment in cell 7b and submit this information to FAA with the form.
B-7
Appendix C C-1 Appendix C. MPE and NOHD for a Laser Emitting Multiple Wavelengths from the Same Aperture C.1. Introduction Some lasers emit multiple wavelengths from the same aperture (beams are coaxial and superimposed). For example, an RGB laser mixing three colors to make a single white beam, or a DPSS (diode-pumped solid-state) laser emitting both visible and infrared light in the same beam. To submit information for a laser that emits multiple wavelengths from the same aperture, follow the steps below.
Complete section 12a.
• Enter “See attached” in the “Laser type” cell.
• List all emitted wavelengths in 12a.
• Create a separate document to record the remainder of the laser’s (12a) characteristics and resulting calculated values for each wavelength. Determine some of these values by completing the following steps.
• Attach the document to the submission, and list the document as an attachment in cell 7b.
Determine the laser’s MPE and NOHD: Given the wavelengths of the laser, use Table 1 and/or Table 2 to determine the MPE for each wavelength with the following steps.
NOTE: Each table groups wavelengths that have the same MPE into rows.
• If all emitted wavelengths are within the same row of Table 1 or Table 2 (they all have the same MPE):
o Enter the value into the MPE cell of section 12b.
o Add the power (W) or energy per pulse (J) of each wavelength together. Use this total power for the calculation in section 16.2.1, Slant Range (NOHD).
o Return to Appendix A to assist with completing the remainder of the form.
• If the emitted wavelengths are in different rows of Table 1 and/or Table 2 (different MPEs):
o For each row where the laser emits one or more wavelength(s), add the power (W) or energy per pulse (J) of each wavelength together in the row to find the total power or total energy per pulse for that row. Enter the MPE for that row and the total power or energy per pulse into the separate document.
Appendix C C-2 o For each row, use the total power or total energy per pulse and the MPE to determine the slant range NOHD as per section 16.2.1., Slant Range (NOHD), and enter it into the separate document.
o After determining the slant range NOHD for each wavelength or groups of wavelengths within a row, determine which of these are in the retinal hazard range of 400 nm to 1320 nm, and which wavelengths are in the corneal hazard ranges of <400 nm or >1320 nm.8 o Repeat the following steps once for all slant range NOHDs (NOHDSR) of the wavelengths within the retinal hazard range (if any), and once for all NOHDSR of the wavelengths within the corneal hazard range (if any).
▪ Square each of the NOHDSR values.
▪ Add all squared slant range NOHDs.
▪ Take the square root of the total to obtain the slant range NOHD of the combined (C) wavelengths (NOHDSRC) within the given hazard range (retinal or corneal).
Equation 70-1.14: Calculating NOHDSRCiv 𝑁𝑂𝐻𝐷𝑆𝑅𝐶 = √((𝑁𝑂𝐻𝐷𝑆𝑅)2 + (𝑁𝑂𝐻𝐷𝑆𝑅)2 + (𝑁𝑂𝐻𝐷𝑆𝑅)2 + ⋯ ) o On the separate document, enter the NOHDSRC for the retinal hazard wavelengths (if any) and the NOHDSRC for the corneal hazard wavelengths (if any). For each NOHDSRC listed, indicate whether the NOHD is for retinal or corneal hazards.
o In the MPE row of section 12b, enter “N/A – multiple wavelength ranges.”
o In the slant range column of cell 14a:
▪ If the laser has wavelengths only in the retinal hazard range or only in the corneal hazard range, enter the NOHDSRC in feet.
▪ If the laser has wavelengths in the retinal and corneal hazard ranges, enter both slant range NOHDSRC values and delineate (e.g., circle, bold, or underline) the longer value. Example: “1303 ft retinal, 83 ft corneal.”
NOTE: FAA will use the longer value as the eye protection distance for aeronautical review.
o Enter the MPE value and the NOHDSRC value(s) on the separate document.
o Return to Appendix A to assist with completing the remainder of the form.
8 Source note: ANSI Z136.1.