This chapter provides guidelines for adjusting your work surface to increase your comfort and safety. It also contains environmental specifications and regulatory statements. The following topics are covered.
You can increase the comfort and safety of your work environment, and decrease your chances of repetitive strain injuries by following the guidelines given below. These guidelines help you create a healthy and productive work environment.
To browse through additional information on setting up your workstation area, taking frequent breaks, exercises you can do, and practicing safe work habits, click Hardware Central . If your web browser is not loaded, it takes a few seconds to load. (This option is not available if you're viewing this on a remote server.)
Table 6-1 shows recommended guidelines for furniture and system adjustment, as developed by the American National Standards Institute (ANSI). [1]
Local Visual Display Terminal (VDT) guidelines issued by country, state, or municipality may apply and supercede the guidelines in Table 6-1.
Table 6-1. ANSI/HFS 100-1988 Guidelines for VDT Workplace Adjustment
Adjustment | Small Female cm (in) | Midpoint cm (in) | Large Male cm (in) |
|---|---|---|---|
Seat pan height | 40.6 (16.0) | 46.3 (18.2)
| 52.0 (20.5)
|
Work surface height (keyboard and mouse) | 58.5 (23.0) | 64.75 (25.5)
| 71.0 (28.0)
|
Screen viewing height | 103.1 (40.6) | 118.1 (46.5)
| 133.1 (52.4)
|
Screen viewing distance | >30.5 (>12) | >30.5 (>12)
| >30.5 (>12)
|
Screen viewing | 0-60 degrees | 0-60 degrees
| 0-60 degrees
|
Adjustment parameters are defined in Figure 6-1. Guidelines are shown for small females (standing height of 150 cm, or 59 in) and large males (standing height of 185 cm, or 73 in). Midpoints are also interpolated for persons of more average height.
Figure 6-1. Basic Parameters of Visual Display Terminal Workstation Adjustment (Adapted From ANSI/HFS 100-1988)
If you work on a CAD system, you may feel more comfortable using the ranges of adjustment shown in Table 6-2.
Table 6-2. Workstation Adjustments Preferred by CAD Users[a]
Adjustment cm (in) | Mean cm (in) | Range cm (in) |
|---|---|---|
Seat pan height | 54 (21.3) | 50-57 (19.7-22.4) |
Work surface height | 73 (28.7) | 70-80 (27.6 -31.5) |
Monitor center above floor | 113 (44.5) | 107-115 (42.1-45.3) |
Screen viewing | 70 (27.6) | 59-78 (23.2-30.7) |
Work surface tilt | 8.6 degrees | 2-13 degrees |
Monitor tilt[b] | -7.7 degrees | -15 - +1 degrees |
[a] Derived from Grandjean, Etienne. Ergonomics in Computerized Offices. London: Taylor & [b] negative tilt = a forward monitor inclination (top of the screen toward the operator) | ||
The following topics are covered in this section:
 | Caution: This product has several governmental and third-party approvals, licenses, and permits. Do not modify this product in any way that is not expressly approved by Silicon Graphics. If you do, you may lose these approvals and your governmental agency authority to operate this device. |
The O2 workstation conforms to several national and international specifications and European Directives listed on the Manufacturer's Declaration of Conformity. The CE mark insignia displayed on the device is an indication of conformity to the European requirements.
A Manufacturer's Declaration of Conformity is available on the World Wide Web. Look on the system (regulatory) label on the rear or underneath your workstation to determine your CMN (model) number. You need this number to identify the Declaration of Conformity on the Web.
To locate the information on the World Wide Web, enter the following in your browser location window:
http://www.sgi.com/Products/compliance/index.html
Locate and print or save your Declaration of Conformity. Make a note of your CMN number and the date of the Declaration of Conformity here for future reference.
This device complies with Part 15 of the FCC Rules. Operation is subject to the following two conditions:
This device may not cause harmful interference.
This device must accept any interference received, including interference that may cause undesired operation.
This digital device meets with Class B limits of the FCC rules and is intended for both residential and business locations.
This Class B digital apparatus meets all requirements of the Canadian Interference-Causing Equipment Regulations.
Cet appareil numérique de la classe B respecte toutes les exigences du Règlement sur le matériel brouilleur du Canada.
This device complies with Class B electromagnetic emissions limits of C.I.S.P.R. Publication 22, Limits and Methods of Measurement of Radio Interference Characteristics of Information Technology Equipment, Germany's BZT Class B limits for Information Technology Equipment, and with Japan's VCCI Class 2 limits.
The equipment described in this guide generates and uses radio frequency energy. If it is not installed and used in accordance with the instructions in this guide, it can cause radio and television interference.
This equipment has been tested and complies with the limits for a Class B computing device in accordance with the specifications in Part 15 of FCC rules. These specifications are designed to provide reasonable protection against such interference in a residential or office installation. However, there is no guarantee that the interference will not occur in a particular installation.
You can determine whether your system is causing interference by turning it off. If the interference stops, it was probably caused by the workstation or one of the peripherals. To tell if the interference is caused by one of the peripherals, try disconnecting one peripheral at a time to see if the interference stops. If it does, that peripheral is the cause of the interference.
If your workstation does cause interference to radio or television reception, try to correct the interference by using one or more of the following suggestions:
Turn the television or radio antenna until the interference stops.
Move the workstation to one side or the other of the radio or television.
Move the system farther away from the radio or television.
Plug the system into an outlet that is on a different circuit from the radio or television. (That is, make certain the workstation and the radio or television are on circuits controlled by different circuit breakers or fuses.)
Silicon Graphics designs and tests its products to be immune to effects of electrostatic discharge (ESD). ESD is a source of electromagnetic interference and can cause problems ranging from data errors and lockups to permanent component damage.
It is important that while you are operating your workstation you keep the top cover in place. The shielded cables that came with the system and its peripherals should be installed correctly, with all screws/thumbscrews fastened securely.
An ESD wrist strap is included with some products such as memory and graphics upgrades. The wrist strap is used when installing these upgrades to prevent the discharge of static electricity, and it should protect your system from ESD damage.
The O2 workstation is FCC-compliant under test conditions that include the use of shielded cables between the workstation and its peripherals. Your O2 workstation and any peripherals you purchase from Silicon Graphics have shielded cables. Shielded cables reduce the possibility of interference with radio, television, and other devices. If you use any cables that are not from Silicon Graphics, make sure they are shielded. Telephone cables do not need to be shielded.
The monitor cable supplied with your system uses additional filtering molded into the cable jacket to reduce radio frequency interference. Always use the cable supplied with your system. If your monitor cable becomes damaged, a replacement cable should be obtained from Silicon Graphics.
[1] American National Standard for Human Factors Engineering of Visual Display Terminal Workstations