Glossary
MPR-II
The standard originally proposed by the Swedish National Board of Measurement and Testing. It set
maximum levels of electromagnetic radiation emitted by monitors, and has now been adopted as a world
standard. MPR-II defines maximum permitted electrostatic, magnetic and electric field levels measured at a
distance of 50 cm from the center of the monitor (see table).
TCO
In 1991, the Swedish Tjänstemannens Central Organization (TCO, Swedish confederation of Professional
Employees ) set a standard even more severe than MPR-II, especially for alternating electric fields (AEF).
The TCO standard is more severe since not only are the permitted field levels reduced compared with MPR-
II, but the measuring distance is also reduced (see table).
Electromagnetic radiation standards
EMI (Electrical Magnetic Interference)
The electrical and/or magnetic radiation coming from the working electrical or electronic equipment.
EMS (Electrical Magnetic Sustainment)
The ability of electrical or electronic equipment to function properly in the environment with electrical and/or
magnetic interference.
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FFlicker
Very rapid variations in picture intensity caused by the finite time required for the electron beam to scan a
picture onto the screen. Two kinds of flicker occur: line flicker caused by the electron beam scanning-in
each line of the picture; and frame flicker (or field flicker if the picture is interlaced) caused by the frame
repetition rate of 50 frames/second. Frame flicker is noticeable with GUI and DTP software (which have a
light background), and can be very disturbing, especially for those who work regularly with displays -
contributing to eye strain, headaches, visual blurring, stress, etc. The problem can, however, be eliminated
by increasing the refresh rate (number of frames/second) of the monitor to a value above around 70 Hz.
Sensitivity to flicker appears to diminish with increasing age.
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