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Laser
Accessories / Laser
Safety Eyewear / How to Select Laser Safety
Eyewear
How to Select Laser Safety Eyewear
Lasermate
Group, Inc. provides a vast range of
laser safety glasses, goggles and eyewear. For step-by-step process on how to
select eyewear, please see below tutorial guideline.
Step
1: Filter
-
Determine
the Optical Density (OD) for wavelength and power of the laser.
-
Consult
the laser manufacturer or refer to laser manual for eyewear
requirements.
-
Consider
the conditions and needs of the use (i.e. eye protection, visible
alignment, flashlamp/IPL).
-
Confirm
that the filter will reduce possible energy exposure to below the
Maximum Permissible Exposure (MPE).
Optical
Density (OD)
is a measure of the attenuation of energy passing through a
filter, where the formulation is as follow: OD = log10(1/T)
or T = 10-OD where OD is optical density and T is the
transmittance. The higher the OD value, the higher the
attenuation and the greater the protection level.
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OD
to % Transmittance Conversions
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|
OD
|
Transmittance
|
OD
|
Transmittance
|
|
0.0
|
100%
|
5.0
|
0.001%
|
|
1.0
|
10%
|
6.0
|
0.0001%
|
|
2.0
|
1%
|
7.0
|
0.00001%
|
|
3.0
|
0.1%
|
8.0
|
0.000001%
|
|
4.0
|
0.01%
|
9.0
|
0.0000001%
|
-
Consider
the Visible Light Transmittance (VLT) of the Filter.
Visible
Light Transmittance (VLT)
is the percentage of visible light transmitted through a filter,
calculated against the spectral sensitivity of the eye to daylight.
Typically the higher the VLT, the lighter the color of the filter.
High VLT is most suitable for low-light environments. VLT values below
20% is suggested to be used in well-lit working environments.
Other
Terms:
L-Rating in EN207 standard is used as the damage threshold of the eyewear material
and requires actual laser stability testing for at least 10 seconds for
CW mode of 100 pulses for pulsed modes. L-Rating consists of three
components: a wavelength range, a laser mode designation and a scale
number. The wavelength range engraved on the laser safety glasses or
goggles is given in nanometers and is significant since the level of
protection provided by the laser safety eyewear is wavelength dependent.
Please refer to European standard EN207 for detailed information.
Filters
can be selected by Wavelength or by Application.
Step 2: Frame
-
Select
Frame style.
-
Consider
whether users require a frame option that fits over prescription
glasses or an adjustable frame to accommodate a variety of faces.
-
Ensure
that the selected frame meets individual needs, and is
face-forming and well-fitting with no gaps.
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