Endress+Hauser SpectraSensors 2-Pack Analyzer System Hardware Installation And Maintenance Manual page 91

The sample cell assembly contains a low-power, 10 mW
maximum, CW Class 3b invisible laser with a wavelength between
750 to 3000 nm. Never open the sample cell flanges or the optical
assembly unless the power is turned off.
Always handle the optical assembly by the edge of the mount.
Never touch the coated surfaces of the mirror.
6. Look inside the sample cell at the top mirror using a flashlight to
ensure that there is no contamination on the top mirror.
SpectraSensors does not recommend cleaning the top mirror.
Contact Service if the top mirror is visibly contaminated (refer to
"Service Contact" on page B-31).
7. Remove dust and other large particles of debris using a bulb blower
or dry compressed air/nitrogen. Pressurized gas duster products are
not recommended as the propellant may deposit liquid droplets onto
the optic surface.
8. Put on clean acetone-impenetrable gloves.
9. Double fold a clean sheet of lens cleaning cloth and clamp near and
along the fold with the hemostats or fingers to form a brush.
10. Place a few drops of isopropyl alcohol onto the mirror and rotate the
mirror to spread the liquid evenly across the mirror surface.
11. With gentle, uniform pressure, wipe the mirror from one edge to the
other with the cleaning cloth only once and only in one direction to
remove the contamination. Discard the cloth.
Never rub an optical surface, especially with dry tissues, as this
can mar or scratch the coated surface.
12. Repeat with a clean sheet of lens cleaning cloth to remove the streak
left by the first wipe. Repeat, if necessary, until there is no visible
contamination on the mirror.
13. Carefully replace the mirror assembly onto the cell in the same
orientation as previously marked making sure the O-ring is properly
seated.
14. Tighten the 4 socket-head cap screws evenly with a torque wrench
to 30 in-lbs (28 m or 8 m measurement cell) or 13 in-lbs (0.1 m
or 0.8 m measurement cell).
Hardware Installation and Maintenance Manual
Maintenance and Troubleshooting
–
B 7