Tolerances / Surface quality
Tolerances for all GRIN single lenses:
- lens length zl: ± 5% due to variations of the gradient constant
- working distance s: ± 0.02 mm
- diameter d: + 0 / -0.01 mm, tighter diameter tolerances on request
- 5 / 3x 0.025
- L 3 x 0.005
- E 0
- all values defined by DIN ISO 10110 7 2000 02
- clear aperture: 90% of the lens diameter
- The surface quality is defined within the clear aperture. Outside of this area defects are allowed.
Storage, Handling and Cleaning
GRIN lenses and lens systems should be stored in a dry environment. For short term storage, the plastic box or foam packing in which the lenses are shipped will provide adequate storage.
Recommended storage temperature: -20°C - 80°C.
Storage boxes should ensure that the lenses do not touch each other to prevent chipping and scratches. Best is to use the original box.
Lenses should be carefully handled with plastic tweezers, preferably those with a tapered end. Lenses should be picked up out of their individual compartments by firmly holding each on its side cylinder surface (not the polished ends). Especially small sized lenses may stick to the lens box material and can be lost during removal.
If it is necessary to clean the lens surfaces due some dust or other contaminant which may impair the optical performance GRINTECH generally recommends the use of ethyl alcohol as a cleaning solvent maybe combined with some smooth lintfree lens cleaning tissue.
Acetone may also be used, but it should be pure enough otherwise it can leave some residue on the lens surface.