Since monitoring involves considerable expenditure of time and money, any monitoring strategy has to be devised very carefully. The strategy should be aimed at gaining maximum knowledge of exposure levels and their impact on the health and safety of people and general environment, within minimum possible time and expenditure of resources. Several factors have to be taken into consideration while carrying out monitoring of personal exposure. At certain times they may be at peak, while at others they may not be harmful. Methods for personal monitoring A brief discussion of the types of techniques used in personal monitoring will be helpful in making decisions for selecting a monitoring method.
Some questions have to be asked before selection of the method.
One simple example of direct reading instruments is the ordinary thermometer. A large variety of instruments are now available which give instantaneous results of the amount of contamination present in the air. They may work by electronic, optical, chemical or by a combination of different principles. The accuracy and consistency of instruments may vary from one technique to the other. Colour detection tubes are an easy tool for detection of the concentration of airborne contaminants and usually come in handy because of their ease of use and portability.