HP 8167A, User Manual, Page: 236 / 262

E
Cleaning Large Area Lenses and Mirrors
Caution
Some mirrors , such as those from a monochromator , are very soft and sensitive . Therefore , never
touch them and do not use cleaning tools such as compressed air or polymer lm.
Some lenses have special coatings that are sensitive to solvents , grease , liquid and mechanical
abrasion. T ake extra care when cleaning lenses with these coatings .
Lens assemblies consisting of several lenses are not normally sealed. Therefore , use as little liquid
as possible , as it can get between the lenses and in doing so can change the properties of
projection.
Preferred
Procedure
1. Blow away any dust or dirt with compressed air .
Procedure for
Stubborn Dirt
Use this procedure particularly when there is greasy dirt on the lens:
Caution
Only use water if you are sure that your device does not corrode .
Do not use hot water as this can lead to mechanical stress , which can
damage your device .
Make sure that your liquid soap has no abrasive properties or perfume in it,
because they can scratch and damage your device .
Do not use normal washing-up liquid as sometimes an iridescent lm remains .
1. Moisten the lens or the mirror with water .
2. Put a little liquid soap on the surface and gently spread the liquid over the
whole area.
3. W ash o the emulsion with water , being careful to remove it all, as any
remaining streaks can impair measurement accuracy .
4. T ake a new , dry soft-tissue and remove the water , by rubbing gently over
the surface using a small circular movement.
5. Blow away remaining lint with compressed air .
Alternative
Procedure A
T o clean lenses that are extremely sensitive to mechanical stress or pressure
you can also use an optical clean polymer lm. This procedure is
time-consuming, but you avoid scratching or destroying the surface .
1. Put the lm on the surface and wait at least 30 minutes to make sure that
the lm has had enough time to dry .
2. Remove the lm and any dirt with special adhesive tapes .
Alternative
Procedure B
If your lens is sensitive to water then:
1. Moisten the lens or the mirror with isopropyl alcohol.
2. T ake a new , dry soft-tissue and remove the alcohol, dissolved sediment and
dust, by rubbing gently over the surface using a small circular movement.
3. Blow away remaining lint with compressed air .
E-10 Cleaning Procedures