PerkinElmer RamanFlex 400, Getting Started Manual

Page: 24 / 94

24 . RamanFlex 400 Series Getting Started Guide
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
Where λ is the laser wavelength in micrometers ( µ m). For example, a laser wavelength of
785 nm (0.785
µ
m) will have an
MPE
value of 1.49 x 10
−2
J cm
−2
or 1.49 x 10
−3
W cm
−2
for
a 10 second exposure or longer. Table 2 shows the calculated nominal ocular hazard distance
for 785 nm Raman systems.
Table 2
Nominal Ocular Hazard Distance (NOHD) for 785 nm
Probe focal length / mm
NOHD for 100 mW exiting fiber optic probe / cm
7.5 (± 10%)
27.3
NOTE: Other focal lengths are available; contact PerkinElmer for details. In particular, the
use of an ultra-long working distance lens adaptor (part number L1320071) provides
a working distance of 25 mm. Where different focal lengths are used, the NOHD
should be calculated accordingly.
Internal Interlock System
There is no internal interlock system fitted to the RamanFlex 400. If instrument panels are
removed collimated laser light may be visible. Under no circumstances remove any
instrument panels.
External Interlock System
Class 3B laser systems have the potential to cause harm or injury to those using them or
others in the vicinity of the instrument. For more information refer to
Attaching the External
Interlock Override
on page 44.