What is glare?

Glare is defined as the light within the field of vision that is brighter than other objects to which the eyes are adapted. The most common sources of office glare are from ambient light sources, such as sunlight from windows and overhead lighting. This ambient light can shine on the glass front of CRT monitors, reducing contrast and creating annoying bright reflections.

"First surface glare" is the reflection or washout generated by the glass surface of a monitor or computer filter. First surface reflection is only reduced through the use of an anti-reflection coating on the computer filter or the surface of the monitor. All 3M computer filters have an anti-reflection coating to reduce first surface glare.

"Reflected glare" is the amount of ambient light which passes through a computer filter, reflects off the monitor face, and passes back through the computer filter. 3M Circular Polarizing computer filters eliminate up to 99% of reflected glare.

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How do 3M computer filters enhance contrast?

Monitor contrast is how bright the display's characters (information) appear against the background. Increasing the monitor contrast makes it easier to read the information being displayed on the monitor. Contrast ratio (CR) which equals character brightness divided by background brightness (including the effects of ambient light) numerically specifies contrast. The larger the contrast ratio, the brighter the information appears against a dark background. A minimum contrast ratio of three (3) is specified by the American National Standard for Human Factors Engineering of Visual Display Terminals.

All 3M computer filters improve the contrast by minimizing first surface glare through the use of an anti-reflection coating. In addition, all models uniformly filter out ambient light using a neutral density filter applied to the glass. The "double" filtration of ambient light as it passes through the filter improves contrast significantly by reflecting off the monitor and passing through the filter again.

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How does the circular polarizing feature work?

3M computer filter models HF300 and HF350 are extremely effective light-trapping devices that reduce glare and increase contrast of monitors. These filters select and alter the properties of light to more effectively remove monitor glare. The ambient light that causes glare and reflections is trapped by the circular polarizer. The light that has passed through a circular polarizing filter and reflects off a surface, such as a monitor, cannot return through the filter, and is absorbed by the polarizing layers. The light from the monitor passes through the filter with far less reduction in strength. The circular polarizing filter allows the images from the monitor to pass through easily.

3M circular polarizing computer filters reduce up to 20 times more glare and improve contrast up to 14 times more than non-filtered computer monitors.*

* Dependent upon monitor and lighting conditions.

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What does "privacy feature" mean?

3M privacy filters offer easy, effective solutions to protect on-screen data. These models feature a patented "microlouver technology," which prevents bystanders from viewing on-screen data from either side of a monitor. Only an operator seated directly in front of the computer monitor can read displayed information. From the side, passersby see only a dark, blank screen.

The black microlouvers reduce the horizontal viewing area to 60 degrees. The light cutoff provided by the black microlouver is complete and does not distort or blur images from the monitor.

In addition, 3M privacy filters simulate a tiny venetian blind to shield out unwanted ambient light, thus incrementally increasing the effectiveness of glare reduction and contrast enhancement.

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What radiation issues should I know about?

Where it comes from

Radiation is generated by the internal electrical components of the monitor and is emitted from out of the back and sides of a computer monitor as well as in front. Because of manufacturer's differences in configuration and shielding of the internal electrical components, emissions may be greatest from either direction.

What it is

The type of radiation emitted from computer monitors is not "radioactive." It isn't as energetic as the type of radiation used by nuclear power plants. The electromagnetic radiation emitted from computer monitors is called extremely low frequency (ELF) and very low frequency (VLF) radiation. All devices requiring electric power will generate ELF and VLF radiation.

Health risks of ELF/VLF radiation

Studies conducted by various federal agencies and independent researchers are inconclusive. Although believed to be nonhazardous, effects most often linked with long-term exposure to ELF/VLF radiation include miscarriages and childhood leukemia.

What 3M anti-radiation filters do

Both ELF and VLF electromagnetic radiation have an electric (E-field) component and a magnetic (H-field) component. When properly grounded, 3M anti-radiation computer filters block up to 99.9% of the electric field (E-Field) ELF/VLF component of low frequency radiation emitted out of the front of the monitor.

The magnetic (H-field) component is virtually impossible to shield. Magnetic fields pass through most materials, including concrete, steel, and lead. The greatest reduction in H-field emission is achieved by wrapping the internal electrical components with a very expensive material called mu metal.

All 3M filters are tested by an independent laboratory that specializes in compliance testing. (Laboratory reports are available upon request.) Using these filters can help monitors meet E-Field ELF/VLF radiation guidelines and voluntary standards such as MPR-II and TCO.

UV light emissions

The main source for ultra-violet (UV) light is sunlight. Insignificant amounts of UV are emitted by a computer monitor and are related to the emission spectrum of the phosphor and pose no known health concern for office workers. All glass provides excellent blockage of UV light. UV light is the invisible region of the spectrum just beyond the violet end of the visible region of electromagnetic radiation. It is defined in ranges per ANSI Z87-1-1989:

UVA Range: 320-400 nanometers
UVB Range: 240-320 nanometers
Total UV: 240-400 nanometers

3M Computer Filters block up to 96% of the total UV range.

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What protection is provided by the anti-static feature on 3M computer filters?

An electrical charge can build up uniformly over a non-conductive glass surface, such as a computer monitor. Conductive coatings with proper earth ground provide a path for discharging this electrical charge build-up. Almost all 3M Computer Filters feature a conductive coating and grounding cord with clip to provide the path and grounding mechanism for full discharge of the electrical charge buildup.

3M Computer Filters with the anti-static feature discharge an electrostatic buildup of 5000V in less than 0.1 seconds when properly grounded. They are independently tested to assure static discharge performance.

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How do I properly ground 3M computer filters for the anti-radiation and anti-static features?

3M Computer Filters with anti-radiation and/or anti-static features are supplied with a grounding cord clip. The ground cord must be connected to the nearest known electrical earth ground in order for these features to work effectively.

The ground cord clip can be attached to a metal frame on the back of a central processing unit (CPU), any metal screw on the back of the unit that makes direct contact with the metal frame, or the metal fan vent on the back of the CPU. For extra safety, unplug the unit while making this connection.

Other typical electrical ground locations are electrical conduit, water pipe, heater vents, and a metal building frame. A small area of paint might need to be scraped away in order to make better contact with the metal.

CAUTION: To avoid electrical shock, do not connect the ground cord to electrical outlets. If you are not sure about grounding the computer filter, contact a licensed electrician.

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How do I clean a 3M computer filter?

Most 3M Computer Filters have Scotchgard™ Protection for Easy Clean Surface, which makes them simple to clean with just a damp, soft cloth.

To clean the coated glass surface of a filter, remove the filter from the monitor and place it on a flat surface. Visually inspect the filter to ensure the glass surface is free from abrasive material. To prevent fingerprinting, avoid touching the glass surface.

For 3M Standard Models and Notebook Models that do not have the Scotchgard™ Protection for Easy Clean Surface, using 3M™ Screen Cleaner 675 is recommended. (For availability of this cleaner, check with the company from which you purchased the filter.) Spray the applicator with the cleaner (one pump should enough.) Reapply if necessary. Wipe clean and dry with the "Clean Hands" applicator. When the applicator becomes stained, detach soiled wipe from the applicator by pulling the outer tab. This exposes a clean wipe. Repeat above cleaning procedure if necessary.

If 3M™ Screen Cleaner 675 is not available in your area, use a vinegar-based glass cleaning solution that is 3 parts vinegar to 7 parts water. Or you might try isopropyl alcohol. Wash with soft cloth and let dry. If streaking occurs, wash with a vinegar solution to remove the streaks.

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