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Digital and analogue methods of data transmission and communication are discussed in order to show their application potential for gas chromatographic data. Digital methods are clearly advantageous for long distance or high data rate transmission. Analogue methods can provide alternative solutions for local range transmission. Analogue transmission by an intensity method in current mode promises to provide a low cost link between gas chromatographs and computer peripheral equipment at the same plant site.

The feasibility of using baseband signaling techniques for data transmission over multipair wireline cable plant is examined. The limit of transmission distance over 19 AWG and 22 AWG non-loaded wire pairs is determined by computing the eye patterns for polar NRZ signaling for various data rates. Polar NRZ signaling was implemented and tested on existing wireline data transmission links, and results were compared with theoretical predictions. The results showed that significant transmission distances can be achieved by using simple and inexpensive polar NRZ techniques. Other baseband techniques such as bipolar signaling at described and recommended as candidates for extremely long multipair wireline cable links and/or high data rate transmission.

New applications for millimeter waves have been developed and will be described. These include: high data rate communications, secure communications, low altitude RADAR, obstacle avoidance, imaging and fog penetration, radiometry and radiometric imaging.