relative humidity of 8 to 80 percent. However, we in the computer  community  try  to  keep  all  magnetic  media within  a  temperature  range  of  60  to  80  degrees Fahrenheit, and a relative humidity of 30 to 60 percent. Generally  speaking,  a  temperature  and  humidity  in which you are comfortable will also be comfortable for diskettes. The users must also be made aware that they are to keep all types of magnetic media, including diskettes, at least  one  foot  away  from  anything  that  generates  a magnetic field. This includes magnets of any kind, such as those found in telephones, stereo speakers, and paper clip dispensers, as well as magnets on copyholders and inside of printers. It also includes motors, such as those found in portable fans and floor buffers and polishers. System Care and Operator/User Maintenance The fact that microcomputer systems are small and out  in  the  workspaces  doesn’t  mean  they  don’t  need operator  maintenance.  They  do.  Dirt  accumulates  on diskettes,  disk  drives,  printers,  display  screens,  and keyboards.  Static  electricity  can  also  be  a  major problem, especially in areas where humidity is low. Keep your system as clean as possible. One way to do this is by using dust covers. This, of course, only protects the system when it is not in use. You will still need to clean the components on a regular basis. Clean  the  floppy  disk  drive  heads  with  a  head cleaning diskette. It is easy to do. Read the directions that come with the head cleaning kit. They may have you put fluid on the cleaning diskette. Then you insert the cleaning diskette in the drive and activate (lower) the heads for a few seconds. This helps reduce service calls, and you are less likely to lose data. How often you will need to do this will depend on how much the system is used and whether the area is very dusty and smokey. Some   floppy   disk   drive   manufacturers   recommend cleaning the heads no more than twice a year. As your subject   matter   experts   (SMEs),   we   recommend cleaning the heads after 40 to 50 hours of actual use. To clean keyboards, you can use specially angled swabs with cleaning solution, and/or a portable vacuum that  has  special  attachments  to  reach  between  keys. Vacuums of this type usually have dual-filter systems to keep from blowing dust and dirt back into the room. Ultra  soft,  thin  bristle  brushes  are  also  available  for cleaning  keyboards.  We  do  not  recommend  you  use 2-30 low-pressure  air  or  canned  air  (a  harmless  gas  under pressure),  as  this  cleaning  method  has  a  tendency  to blow dust and dirt into cracks, crevices, and electrical components that could eventually cause you problems. The display screen needs routine cleaning. A dirty screen  can  be  hard  to  read  and  may  contribute  to headaches and fatigue. You will be able to see the dirt, dust, and smoke buildup on the screen. The dust can cause static electricity that may result in lost data. You may use a liquid video spray cleaner, but do NOT spray it  on  the  screen.  Spray  it  on  a  lint-free  nonabrasive cloth. A word of caution. Many commercial cleaning solvents  contain  alcohol  and  other  flammable  agents.  If your display screen is on (energized) when it is cleaned with  one  of  these  flammable  fluids,  combustion  can occur. An energized display screen can discharge quite a bit of static electricity-—a  sufficient  amount  to  ignite alcohol. So, if you intend to clean your screen, turn the monitor   OFF  first. Also   available   are   wet/dry towelettes.  These  are  convenient  to  use  because  the cleaning  solution  is  normally  premeasured  and  they come  in  individual  packets.  To  reduce  static  electricity, special antistatic sprays are available, or you can use antistatic   pads   or   mats. Some   cleaning   solutions include antistatic chemicals. An antistatic filter for the display screen is another way to reduce static buildup. Antistatic dust covers may also help when the system is not being used. Printers create their own bits of paper and dust. To clean  the  printer,  use  a  vacuum  designed  to  clean computer   components.   These   vacuums   are   usually portable, have a dual filtering system, and can clean in small,   hard   to   get   places.   Cleaning   solutions   and specially  shaped  brushes  are  available  for  cleaning platens.  For  cleaning  the  print  heads,  you  can  feed  a specially   designed   print   sheet   cleaner   through   the printer just like you feed continuous-form paper. Laser printers  have  special  cleaning  requirements.  You  use dry lint-free clothes to wipe any residue of surfaces and a cleaning brush to clean the antistatic teeth. Operator/user   maintenance   is   important   for effective   operation   of   computer   systems. It  helps prevent  data  loss  and  will  increase  the  life  of  the computer   system   and   its   components.   Establish schedule for routine operator/user maintenance. a