History of Sensor Technology

[based on a text by the Spanish CSIC from 1987]

The human beings have always tried to foresee the effects of the different phenomenons in nature. Those having methods to know how to e.g. mix a certain medicine acquired big power due to the lack of knowledge of the rest. Knowledge would be hidden behind secret mystical rituals until the rise of science.

Science was constructed through experiments that would relate two basic concepts:

  • values for the different measures intervening as part of an experiment
  • mathematical expressions that relate those values to each other

With science humankind gets introduced to the idea of measuring; operation that has to be done prior to analysis. Measurements of physical variables can only be understood through the comparison of two different states. Choosing what we call a reference value we create a standard or scale where to compare whatever value we measure to others.

The different standards were carved in the stones on the gates to many medieval European cities. This established a discussion platform for the citizens, a negotiation tool for businessmen, and a ruling tool for the leaders.

During the medieval age, city councils were the authority determining the scales or measuring patterns. Later, with the creation of states and appearance of nations, the standards expanded their coverage to whole regions and countries. The combination of groups of standardized units of measure is what we call the systems of units. At some point of history there existed different types of systems, but nowadays every country is migrating to the so-called metric system.

The basic things we can measure, according the the International System of Units are:

  • the meter for distance,
  • the kilogram for mass,
  • the second for time,
  • the ampere for electric current,
  • the kelvin for temperature,
  • the mole for amount of substance, and
  • the candela for intensity of light

All the other units you can imagine like the volts for electricity, or the hertz for frequency can be derived from the above mentioned ones.

Once defined units and scales to measure physical variables, we can start to relate our work with the one from others. This has boosted the development of science through the comparison of results coming from different researchers.

However, when working with sensor technology we don't always need to relay on how

References:

  • How Many? A Dictionary of Units of Measurement by Russ Rowlett and the University of North Carolina at Chapel Hill
  • Introduccion a los sensores, Consejo Superior de Investigaciones Cientificas (CSIC), Centro para el Desarrollo Tecnologico Industrial (CDTI), Ed. El Museo Universal, ISBN: 84-00-06624-3, Madrid 1987