Philips 107T21-74 User Manual
Page 26
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.
F
Flicker
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.
H
Hertz
The unit of frequency named after the physicist Heinrich Hertz (1857-1894). 1 hertz (Hz) is equal to 1
cycle/second.
Horizontal dot pitch
See Dot pitch.
Horizontal scanning frequency
Glossary
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