Overview Applications

Moisture measurement in solids or liquids ever has been very application related. "Normal" physical properties of matter like temperature or pressure always are well defined features of condition, that can be measured in few standardizable scenarios. But this situation is already changing for humidity measurement.

Moisture measurement in materials multiplies the specifity of application. Fundamentally in each material moisture measurement it is necessary to take into consideration physical and chemical characteristics of material under test, which are influencing the form of water appearing in this sample. This is concerning the mechanisms of input and output of water and the types of water binding in that water is present in materials, which also can be found in combination.

An essential role are playing materials structure, the presence of pores and their shape, the inner surface, the density, but also special chemical properties. The consideration of all these properties in a materials moisture model would lead to an enormous effort in laboratory work probably followed by the development of a new moisture sensor adapted to the application. In the past this was the way moisture measurement problems always were solved, but always for sharply limited applications. So there are existing special moisture meters for wood, for civil engineering, for grains, for bulk goods etc.

It is clear that such manyfold definitions, ideas, concepts and different technical solutions lead to a certain amount of confusion. A standardization of material moisture measurement like for other sensors and material properties is not possible this way.

The only help in this situation is a modular concept of moisture sensors, which provides for different applications always the best suited moisture sensor following a systematic scheme. The MOIST system is such a modular system of moisture sensors.

The MOIST series of microwave based material moisture measuring systems was designed in a modular way. So for many applications in solids or liquids microwave sensors well adapted to the measuring task can be found or configured to a sensor arrangement.

The table gives an overview of different measuring principles and the possibilities of the MOIST modular system: