ABSTRACT
Field ionization humidity sensors analyze the ionization characteristics of air containing water vapor. Field ionization is a quantum tunneling phenomenon whereby an atom or a molecule is ionized in the presence of a very high electric field, typically of the order 1010 V/m. This type of sensor can detect gases regardless of their adsorption energies. These sensors can be used to measure humidity in applications in which the fast response is essential and the need for compensation of the moderate temperature and pressure changes can be tolerated. This chapter discusses approaches that can be used to develop such sensors. The focus is on the consideration of gas ionization sensors based on one-dimensional structures. The materials used to develop such sensors and sensor performances are also analyzed.
