Dew Point Analyzers, otherwise known as the DEW point detectors are used to measure air content, soil moisture, and ground temperature in order to detect the amount of dew point air in a particular area. The DEW point is the main value in the laboratory measurement of soil moisture, because it indicates the moisture content as a function of the earths average dew point, which occurs at the transition between night and day.
The average of the dew point for a given area is called the Claussell curve, and this curve was first established by Claussell and Pierson in 1908. The reason why the dew point is used in the measurement of moisture content is that it is the saturation level of the soil at its dew point, which can be defined as the exact temperature at which vaporizing water will begin to replace dry air. This temperature is very sensitive to changes in external temperatures, especially those that occur naturally such as rainfall or snowfall, and any change in the temperature can cause an imbalance in the moisture content.
A good dew point analyzer should include a permanent moisture measurement option as part of its measuring device. While the traditional method of moisture measurement, called the wet-vac system, relies on a manual method where a controller is used to set the parameters of the device and maintain them for accuracy, the new wet-vac system makes use of a microprocessor that controls and measures the parameters continuously. The benefit of the wet-vac calibration system is that it automatically adjusts to any changes in the soil moisture level and displays the readings as accurate, whereas other methods of moisture measurement require more manual adjustments and require calibration on a regular basis. Another advantage of the wet-vac calibration method is that the instrument can perform more than one measurement simultaneously.
There are a number of different types of dew-point analyser available for use in the field. There are hydrometer types that measure the amount of dissolved gas, water vapor and humidity. There are also dew point hygrometers that measure the amount of ground water that exists in a specific area. Some dew point hygrometers measure the amount of total dissolved organic compounds in the soil as well.