32
Guidelines for Productive and Healthy Use of Your X Terminal
You may have read or heard of articles which have linked prolonged viewing of computer video display terminals with eye fatigue,
and prolonged use of computer keyboards and mouse devices with repetitive stress injuries such as carpal tunnel syndrome. One
common example is the syndrome known as “tennis elbow.” Although a conclusive direct causal relationship between computer
use and these adverse health effects has yet to be scientifically proven, NCD recommends that you read and follow these guidelines
in setting up and using your new NCD X terminal.
•
Set up your X terminal in a well lit, glare and shadow-free environment.
•
Avoid using your X terminal in a position you find awkward or unnatural.
•
Select a chair that provides good lower back support. Adjust your chair so that your feet rest flat on the floor with your
thighs in a horizontal position.
•
Place your keyboard on a surface so that your wrists are not tilted, or only slightly tilted while using the keyboard. Many
people find a comfortable keyboard height is at the same level as their elbows.
•
If the height of your work surface cannot be adjusted, position the chair at a comfortable height and use a footrest to place
your feet on a level surface.
•
Place your mouse on a surface which is at the same height as your keyboard. Many people find using the mouse and
keyboard within 16" inches of the body is comfortable.
•
Avoid resting your arm on your work surface and merely bending your wrist when using your mouse. Consider using a
wristrest to provide a padded surface for your wrists when working with your mouse.
•
Place your display monitor at a comfortable viewing distance. Many people favor a distance of 16" to 28" from their eyes.
Position the screen so that you are not looking up or down at the screen.
•
Take breaks to rest your eyes, stretch your muscles, and move around.
•
Vary your work patterns so that you alternate working at your X terminal with other tasks that use different muscle groups
and allow you to focus your eyes at different distances.
•
See your physician if you experience persistent muscle ache, joint pain, eye fatigue or other discomfort when using your X
terminal.
These are guidelines. What is comfortable for some may not be comfortable for you. You are the only one who can decide if these
guidelines are appropriated for your needs.
What about electromagnetic emissions from your monitor?
Many objects we encounter in our everyday lives produce very low frequency (VLF) and extremely low frequency (ELF) electro-
magnetic emissions. These objects include such common appliances as portable cellular telephones, televisions, toasters, electric
blankets, and video display terminals (VDT) such as the monitor which is part of your X terminal. VDTs, have been the focus of a
growing controversy over the potential health effect of VLF and ELF emissions.
NCD is monitoring this issue and shares the public’s concern over the potential health consequences of exposure to VLF and ELF
emissions from VDTs. To date, the research and testing on this subject is inconclusive. Moreover, the link, if any between VDT
emissions and adverse health effects is unproven and the subject of much debate. Stress, postural strain and poor working condi-
tions are frequently cited in addition to, and instead of, VDT emissions as posing potential health hazards to frequent users of
VDTs.
The prevailing professional opinion to date is that VDTs are safe. NCD products comply with the applicable regulations and stan-
dards for electromagnetic radiation set forth by the U.S. Code of Federal Regulations, Underwriters Laboratories, Inc., the Canadi-
an Standards Association and the German VDE Standard. When and if new or additional standards are adopted, NCD will take
appropriate steps to comply with them.
Even though the preponderance of professional opinion is that VDTs are safe, some of our customers have asked us for information
on how to reduce their exposure to VLF and ELF emissions. Although NCD does not endorse the following as having health ben-
efits, the easiest and perhaps most economical and effective measures are to turn off your display when not in use, to position your
display at arm’s length, and to avoid working in areas where you are positioned close to the rear of a VDT where the emissions are
strongest. Also, shields are available from third party vendors that reduce glare and electric emissions.
Copyright and Trademarks
The information contained in this document is subject to change without notice. Network Computing Devices, Inc. shall not be
liable for errors contained herein or for incidental or consequential damages in connection with the furnishing, performance, or
use of this material. This document contains information which is protected by copyright. All right are reserved. No part of this
document may be photocopied, reproduced, or translated to another language without the prior written consent of Network Com-
puting Devices, Inc.
Copyright 1995 1996 by Network Computing Devices, Inc.
Trademarks
NCD, Network Computing Devices, and Explora are trademarks of Network Computing Devices, Inc. XRemote is a registered
trademark of Network Computing Devices Inc. LK-401 is a trademark of Digital Equipment Corporation. Ethernet is a trademark
of Xerox Corporation. UNIX is a registered trademark of UNIX System Laboratories, Inc. Token-Ring, PS/2, and IBM are registered
trademarks of International Business Machines Corp. TROPIC is a trademark of National Semi-Conductor Inc. PCMCIA is a trade-
mark of PC Memory Card International Association. X Window System is a trademark of X Consortium. SIMM is a trademark of
Wang Laboratories, Inc
.
Revision History
Part Number 9300351 Rev A, August 1995 -- First release of this document
Part Number 9300385 Rev A, November 1995 -- Changed name to Explora
