This chapter gives you some important information on safety and comfort, as well as some helpful hints on maintaining your IRIS Indigo workstation. It also provides important regulatory information.
This section gives you some basic guidelines to follow to keep your hardware, and the software that runs on it, in good working order.
To keep your workstation in good running order, try to remember these guidelines.
Do not
enclose the workstation in a small, poorly ventilated area (such as a closet), crowd other large objects around it, or drape anything (such as a jacket or blanket) over the top
use the workstation as a shelf or table
run the workstation with the front plastic cover off; this alters the air flow
connect cables (other than audio) or add other hardware components while the workstation is turned on
power down the workstation frequently; leave it running over nights and weekends if possible
move the workstation while it is running, or within 1 minute of powering it down; it contains a hard disk that may be damaged
lay the workstation on its side
use an adapter to plug the workstation into a two-prong (ungrounded) outlet
place liquids, food, or heavy objects on the workstation or keyboard
dangle the mouse by its cable or throw the mouse at co-workers
Do
plug in all cables completely
plug the workstation into a power surge protection strip (if possible)
When your system is up and running, follow these guidelines.
Do not
turn off power to a workstation that is currently started up and running software
use the root account unless you are performing administrative tasks
Do
You can increase the comfort and safety of your work environment, and decrease your chances of cumulative trauma disorders, by following the guidelines given below. These guidelines will help you to create a healthy and productive work environment by:
using your workstation correctly
properly choosing a site for your system and its components
setting up your desk and chair correctly
Table 7-1 shows recommended guidelines for furniture and system adjustment, as developed by the American National Standards Institute (ANSI). [1]
Local VDT guidelines issued by country, state, or municipality may apply and supercede the guidelines in Table 7-1.
Table 7-1. ANSI/HFS 100-1988 Guidelines for VDT Workplace Adjustment
Adjustment | Small Female | Midpoint | Large Male |
|---|---|---|---|
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 angle | 0-60 degrees | 0-60 degrees | 0-60 degrees |
Adjustment parameters are defined in Figure 7-1. 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.
If you work on a CAD system, you may feel more comfortable using the ranges of adjustment shown in Table 7-2.
Table 7-2. Workstation Adjustments Preferred by CAD Users[a]
Adjustment | Mean | Range |
|---|---|---|
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 & Francis Ltd., 1987, p. 148. [b] Negative tilt = a forward monitor inclination (top of the screen toward the operator) | ||
The following tips may be useful for setting up an ergonomic work environment that is safe, comfortable, and productive. Although you may be able to perform this procedure yourself, it is useful to work with a friend to achieve the best fit.
A good work chair should swivel, and you should be able to adjust the seat height while sitting. The seat should have a rounded front edge. The chair should have a large enough base to remain stable when adjusted to its maximum height. It should have castors or glides. Many chairs rock, which may partially relieve the muscle tension from sitting in a fixed position. Some chairs can also be adjusted for seat tilt and depth, armrest height, backrest angle, and lower back support. Check the instructions that came with your chair to take advantage of its adjustability features.
Select a work surface that provides enough space to do your work without excessive turning, twisting, or stretching. The height of the work space should be adjustable and, if possible, you should be able to use the mouse and keyboard at the same height. This helps your neck, shoulders, and upper arms stay relaxed while you work.
Indirect lighting should be used, whenever possible, to prevent glare on the display screen. If you prefer lower levels of lighting (for example, 200-250 lx) than is usually found in offices, separate task lighting may be needed for reading documents. Wearing darker-colored clothing helps minimize glare reflections on the screen.
Adjust your chair first, from a seated position if possible. Your lower leg and thigh should form approximately a 90-degree angle at the knee, and your feet should rest flat on the floor. If you are short, you may want to use a footrest for better comfort.
Once your chair is adjusted, raise or lower your work surface to a height that allows you to keep your wrists flat and straight while using the keyboard and mouse. The angle between your lower and upper arm should be 70-90 degrees at the elbow. If necessary, use a padded wrist rest under the keyboard to support your wrists.
To minimize screen glare, position your monitor screen perpendicular to overhead lighting sources and windows. Do not set the monitor in front of or behind a window, or parallel to other sources of light. Tilting the screen forward slightly helps avoid glare. Adjusting the monitor controls to minimize brightness and maximize contrast may also reduce the effects of glare.
Adjust your monitor height so your line of sight in your regular seated position is at or near the top the screen. You should be able to see the whole screen without tilting your head forward or backward, within a 60 degree viewing angle of the normal line of sight. With smaller monitors, this may require using a display stand under the monitor base. With larger monitors, it may require a longer viewing distance (see Table 7-1).
These adjustment steps should be done each time a different person uses the workstation.
When using the keyboard, mouse, or other input devices, keep the wrists flat as much as possible, and do not rotate the hands inward toward the thumbs or outward toward the pinkies.
Electronic keyboards and input devices do not require as much force to operate as manual typewriters. Type or click lightly, rather than pounding on the keyboard or mouse.
Document stands can be mounted on the work surface or can swing out on an arm to position documents next to the display. Such arrangements can be helpful in maintaining a healthy posture for using the workstation (head in approximately a straight line with the body).
You may find it helpful to take rest breaks of several minutes every one to two hours. During breaks, focus your eyes on objects or scenery at least 30 feet away, stretch, and move around.
The following sections provide regulatory information for the IRIS Indigo workstation.
The Indigo R3000 complies with the Class B limits and the Indigo R4400 complies with the Class A limits of 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 equipment does not exceed the Class B limits of Canada's Department of Communications Radio Interference Regulations for radio noise emissions.
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.
 | Caution: Do not modify this product in any way that is not expressly approved by Silicon Graphics. If you do, you may lose your FCC or other government agency authority to operate this device. |
The Indigo R3000 Elan and Indigo R4000 comply with the Class A limits of 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 equipment does not exceed the Class A limits of Canada's Department of Communications Radio Interference Regulations for radio noise emissions.
This device complies with Class A 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 A limits for Information Technology Equipment, and with Japan's VCCI Class 1 limits.
| Caution: Do not modify this product in any way that is not expressly approved by Silicon Graphics. If you do, you may lose your FCC or other government agency authority to operate this device. |
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 digital device in accordance with the specifications in Part 15 of FCC rules. These specifications are designed to provide reasonable protection against such interference in an industrial or office installation. However, there is no guarantee that the interference will not occur in a particular installation. This system is not certified for home use.
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.)
This product has been tested and is listed, certified, or approved to the following product safety standards:
UL 1950
CAN/CSA C22.2, No. 950-M89
IEC 950
EN 60 950
Standard for Safety of Information Technology Equipment, including Electrical Business Equipment, Class1, SELV
This product meets the applicable requirements of ISO 9241, and the European Community Directive 90/270/EEC (Workstation Safety Law) specifications. This product also meets Germany's ZH1/618 requirements for deskside and bookshelf products.
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 IRIS Indigo workstation you keep all the covers and doors, including the plastics, in place. The shielded cables that came with the system and its peripherals should be installed correctly, with all 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 flow of static electricity, and it should protect your system from ESD damage.
The IRIS Indigo workstation is FCC-compliant under test conditions that include the use of shielded cables between Indigo and its peripherals. Your 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.
Silicon Graphics, Inc. warrants this IRIS hardware product, option or accessory against defects in material and workmanship for a period of ninety (90) days after the date of its original retail purchase (the “Warranty Period”). If you discover a defect in the Product during the Warranty Period, SGI will, at its sole option, repair or replace the Product at no charge to you, provided that you (i) return the product (transportation charges prepaid) during the Warranty Period to the authorized SGI dealer (or SGI service center, if purchased directly from SGI) from whom it was purchased, or return it to another authorized SGI dealer in the country of its original purchase, and (ii) have included a copy of a bill of sale bearing the appropriate SGI serial number as proof of the original date and location of the Product's purchase. This warranty applies only to hardware products manufactured by or for SGI and distributed under SGI's trademarks, and does not apply to any (i) SGI software accompanying the Product, which is licensed under a separate statement included with the software, (ii) Product that has been damaged by abuse, accident, misuse, misapplication or improper installation, and (iii) any Product that has been modified or has had its serial number removed or defaced.
The warranties and remedies specified above are exclusive, and are in lieu of, and SGI disclaims, all others, express, implied, oral or otherwise, including, without limitation, any warranty of merchantability or fitness for a particular purpose. No oral or written information or advice given by SGI, or its dealers or distributors, will create a warranty or increase the scope of this warranty, and you may not rely on such information or advice. Some states do not allow the exclusion of implied warranties, so the exclusion above may not apply to you. Any applicable implied warranties are limited in duration to the period of time specified above. This warranty gives you specific legal rights, and you may have other rights that vary from state to state. SGI is not liable for any special, consequential, incidental or indirect damages of any kind (including without limitation loss of profits, data or goodwill, or property damage), whether or not SGI has been advised of the possibility of such loss, however caused and on any theory of liability, arising out of the use of the product, or resulting from a breach of this warranty. These limitations shall apply notwithstanding the failure of the essential purpose of any limited remedy. SGI's liability for actual damages for any cause whatsoever, regardless of the form of action, will be limited to the net amount paid by you for the purchase of the Product that caused the damages or is directly related to the cause of action. Some states do not allow the limitation or exclusion of liability for incidental or consequential damages, so this limitation may not apply to you.
Silicon Graphics, Inc.
2011 N. Shoreline Blvd.
Mountain View, CA 94039-7311
[1] American National Standard for Human Factors Engineering of Visual Display Terminal Workstations