Modern technology

• What does CAD stand for?

  Computer-aided drafting
• What are the disadvantages of CAD?

  • It is only capable of producing a drawing to the standard of which the draftsman is capable of
  • The CAD system is only cost-effective if the type of work performed on it is carefully chosen
• Advantages of CAD:

  • Any detailed drawn once can be repeated as many times as you wish thus saving time
  • Produces good reproduction quality
  • Produces automatic isometric diagrams
• What is scanning?

  Scanning is transforming paper based information into electronic/digital data.
• Commercial scanning


  The commercial field is limited mainly to the scanning of very large volumes of textural data using small flat bed gray scale scanners
• What is Commercial scanning?

  Commercial scanning is when the data is scanned into a computer for storage and screen "view only" purposes.
• Commercial scanning is concerned mostly with very high quality colour scanning which requires particular hardware and software technology
• Computer graphics and large document scanning is mostly concerned with documents sizes up to A0.
• The need of engineering and mapping is to convert the paper documents into an electronic form that can be easily stored (archived), accessed (retrieved), processed (revised) and plotted, using a computer system
• How does a scanner work?

  The document is placed so that it can be scanned by a light source. The intensity of a light reflected from the surface of the paper is modified by any markings on the paper. These could be drafting lines and circles on a drawing. The output from the scanner appears on the computer screen as an image made up of black and white pixels.
• What is resolution?

  Resolution is defined as "dots per inch", or dpi, and you should always be stated in terms of true/ machine resolution.
• 500 dpi gives a pixel size of a proximately 0.05mm x 0.05mm
• What are the advantages of increasing the resolution?

  By increasing the resolution the quality of the screen image can be greatly improved
• What are the disadvantages of increasing the resolution?

  By increasing the resolution the image's file size increases as well
• CAD is only capable of producing a drawing to the standard of which the draftsman is capable
• Advantages of CAD:

  • Save time by relieving the draftsman of tedious work.
  • CAD is useful for line diagrams, both electrical and mechanical, especially pipe work.
  • CAD can also be used for electronic transmission and storage of drawings.
  • CAD terminals can in some instances also be directly attached to Mills and lathes, thus making production fully automatic
• Disadvantages of microfilming:

  Because of the reduction process it is imperative that the drawing line work and printing be of high quality, otherwise the resulting prints will be unreadable and therefore useless
• What is scanning?

  To gather together
• What does scanning mean in a computer-based environment?

  Transforming paper-based information into electronic data
• Commercial scanning is limited mainly to scanning of large volumes of textual data
• Commercial scanning uses small A4 flatbed scanners
• Commercial scanning is mainly used in financial institutions like banking, insurance and other associations
• Computer graphics scanning is concerned with document sizes up to A0
• Commercial scanning uses small A4 flatbed scanners.