WON TECH WON COSJET ATR S, Руководство пользователя

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User Manual
WT-UM-08 (v4.4)
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5 HOW TO USE

Instruction for Use
- Information on the NOMINAL OCULAR HAZARD DISTANCE (NOHD) for the laser equipment
in NORMAL USE with each appropriate ACCESSORY.
NOHD Calculation (WON COSJET ATR S)
1. Genesis mode (1064nm, 0.48ms)
2. Q-switching mode (1064nm, 48ns)
3. Q-switching mode (532nm, 48ns)
1. For the WON COSJET ATR S laser system, determine the intra-beam MPE for direct ocular
exposure to the radiation from a Nd:YAG laser(λ = 1 064 nm) operating at a frequency of F = 1 Hz
with a pulse width of t = 0.48 ms at free running mode.
As the laser does not operate in the visible part of the spectrum, protection is not afforded by the blink
reflex. A reasonable estimate of a hazardous chance exposure time can be taken as 10 s. For this time
period, the total number of pulses is:
N= T F = 10 s 1 Hz= 10
At IEC60825-1:2001, subclause 13.3 includes three criteria which must be considered, and the most
restrictive one applies to this evaluation. The value of C
6
is 1 in these calculations since the beam is
emitted from a small source. The value of C
7
from notes to tables 1 to 4 is also 1 for the 1 064 nm
wavelength.
From 13.3a), the exposure from any single pulse shall not exceed the single pulse MPE. Thus the
radiant exposure from table 6 for the time period of 0.3ms is:
H
single
=90 t
0.75
C
6
C
7
J m
-2
=90 0.0003
0.75
1 1 J m
-2
= 0.205 J m
-2
From 13.3b), the average exposure for a pulse train of exposure duration T shall not exceed the MPE
for a single pulse of exposure duration T. For the 10 s duration (the total exposure time), table 6 limits
the radiant exposure to:
H
single
=90 t
0.75
C
6
C
7
J m
-2
=90 10
0.75
1 1 J m
-2
= 506 J m
-2
Since there are N = 10 pulses in the 10 s period, the average irradiance criteria results in a single pulse
radiant exposure of:
H
single, avg
=
H
T
N
=
506
10
J m
-2
= 50.6 J m
-2
From 13.3c), the average exposure from pulses within a pulse train shall not exceed the MPE for a
single pulse multiplied by the correction factor C
5
(where C5 = N
–1/4
). For the N = 10 pulses in the 1 s
period, the radiant exposure under these criteria would be:
H
PE, train
= H
PE, single
N
-0.25
= 0.205 (10)
-0.25
J m
-2
= 0.115 J m
-2
Since the limit from the repetitive pulse criteria of 13.3 c) is the most restrictive, the single pulse MPE
for this system would be 0.115 J
⋅
m
–2
. The MPE could also be expressed in terms of irradiance as: