PerkinElmer RamanMicro 200 Series, Getting Started Manual

Page: 23 / 98

Safety Practices . 23
•
Controlled access areas, limited to individuals trained in the safe operation of lasers, are
suggested for laser operations.
• When the probe is in use, always ensure that no stray laser radiation is directed at
people in the vicinity.
• Use protective laser safety goggles, with an optical density (OD) of at least 3 at 785 nm,
as a precaution against accidental exposure to the direct or reflected laser light. Suitable
goggles are available from PerkinElmer (part number L1323518).
•
Do not use the TFOP if it shows any sign of damage.
•
If repair or servicing is needed, call your PerkinElmer Service Representative for advice.
For further safety details, see the
Raman Triggered Fiber Optic Probe
leaflet (L1321940)
Calculation of Nominal Hazard Zones for use of Fiber Optic Probe
The following calculations show how to calculate a nominal hazard zone. These calculations
are taken from ANSI Z136.1-1933. A laser safety officer uses these calculations to help
define how to use your Raman probe safely in your environment.
Figure 3 Probe parameters used to calculate the nominal ocular hazard distance
The equation for a focused beam as given here (Figure B5 in ANSI Z136.1-1933) is used to
calculate the nominal ocular hazard distance (NOHD) for the fiber optic probe. The equation
is:
2
1
. Π
Φ 4












=
MPE b
f
NOHD
o
o
Where:
f
o
= Probe focal length (cm)
b
o
= Diameter of laser beam incident on probe focusing lens (mm)
Φ
= Total radiant output power of probe (watts)
MPE =
Maximum permissible exposure (J cm
−2
)
For the FOP
b
o
is 0.254 cm, therefore the above equation can be simplified to give:
2
1
Φ
. 442 . 4






=
MPE
f NOHD
o
For the wavelength range 700–1050 nm the
MPE
for a 10 second exposure can be calculated
from:
( ) ( )
( )
[ ]
4 7 . 0 2
10 10 1 . 10
− −
=
λ
MPE
J cm
−2
b
o
f
o
NOHD