Optical filters are key components in various industrial and scientific applications. Proper maintenance and cleaning are crucial to achieving optimum performance.
This article offers advice on how to best care for Chroma’s optical filter range.
Note: The information provided in this article is based on the standard catalog parts and sizes offered by Chroma Technology.
Best Practices for Cleaning Optical Filters
Working with optical filters in the scientific or industrial sectors requires more than understanding their operation. Proper maintenance and handling are also essential to ensure optimal performance and longevity.
This article outlines the best practices for handling and cleaning Chroma Technology’s optical filters to ensure they continue to operate at their best capacity.
Use Gloves
Gloves must always be worn when handling optical filters. Optics should never be handled with bare hands. Nitrile gloves are an ideal choice due to their durability and chemical resistance.
Gloves should be clean and fit the wearer well. Once the gloves are on, it is advisable to clean them using an alcohol wipe to remove any remaining contaminants on the gloves. Should gloves become damaged, these must be replaced immediately.
Extra care should be taken when handling optical filters to avoid touching hair, face, and unclean surfaces. Doing so could potentially contaminate the gloves and, subsequently, the surface of the optic being handled.
Image Credit: Chroma Technology Corp.
Hold Filters by the Edges
Optical filters and components are extremely delicate and should be handled carefully. Only handle optical filters by the edges; if necessary, place them onto soft, clean surfaces, such as lint-free wipes or lens tissue, to set them down.
It is also important to exercise caution when using tools because these can easily damage optical parts if mishandled.
Cleaning Optical Filters
The first rule of cleaning optical filters is not to clean them if they already appear clean. Unnecessary cleaning can introduce dust and other contaminants, resulting in performance degradation over time.
The environment should be prepared before cleaning. It is important to work in a clean, temperature-controlled space. It is also advisable to work in a darkened area with a black background and light for inspection or in a booth specifically designed for the inspection of optical components.
The primary clean tools are:
- Reagent-grade anhydrous ethyl alcohol or an equivalent cleaning agent
- Lint-free task wipes, i.e., Kimtech Kimwipes or similar
Cleaning Procedure
Blowing off loose dust and debris using a bulb puffer or filtered, pressurized air cleaner is advisable. Ideally, this should be done with clean compressed air or dry nitrogen. It is important to remember that this should never be done by mouth, as saliva and other organic compounds could contaminate the optic.
The optic should only be wiped where necessary. If wiping is required, gently wipe the surface using a combination of reagent-grade alcohol and lint-free swabs or lint-free task wipes.
Lint-free wipes or swabs should be soaked in fresh alcohol before use, and wiping should be performed from the inside out to avoid drawing contaminants from the edge onto the part. Acetone can be used in place of alcohol where required, but it is important not to oversaturate the wipe or swab, regardless of the chemical in use.
When wiping, use a slow, steady drag across the surface. This should be done with minimal force while maintaining a smooth movement. Wipes and swabs should be properly disposed of after use, as reusing them can reintroduce contaminants onto the surface of the optical filter.
Frequently Asked Questions
Is it necessary to clean the optical filters after each use?
No, cleaning optical filters when they appear dirty is advisable. Over-cleaning can introduce additional contaminants onto filter surfaces.
What is the best approach to wiping optical filters when cleaning?
Gently wipe the surface using reagent-grade alcohol and lint-free wipes, but only when necessary.
Lint-free wipes or swabs should be soaked in fresh reagent-grade alcohol, and the filter should be wiped from the inside out to avoid drawing contaminants from the edge onto the part. It is also important to use minimal force and maintain a smooth movement.
Is it advisable to blow on the filters to remove dust and debris?
Never blow on the filter surfaces by mouth, as this can inadvertently introduce moisture and contaminants to the optics. Instead, it is advisable to use clean compressed air or dry nitrogen.
Summary
Handling and cleaning optical filters requires precision, patience, and a thorough understanding of best practices. Following these recommendations will extend the lifespan of optical filters and ensure they continue to perform at their best.
Acknowledgments
Produced from materials originally authored by Chroma Technology Corp.
This information has been sourced, reviewed, and adapted from materials provided by Chroma Technology Corp.
For more information on this source, please visit Chroma Technology Corp.