Microwave water content measurement device and measurement method based on space traveling standing wave attenuation

Abstract

The invention relates to a microwave water content measurement device and a measurement method based on space traveling standing wave attenuation, and belongs to the technical field of microwave applications. The device is composed of a microwave transmitting probe, a sample container, a measured material, a microwave receiving probe, a sliding platform, a lead screw guide rail unit, a motor unit,a weight monitoring unit and a signal display control unit. The sample container of the device is located between the microwave transmitting probe and the microwave receiving probe; the microwave receiving probe is fixed on the sliding platform of the lead screw guide rail unit, and can move freely in the horizontal direction to realize continuous measurement of space standing wave signals. The signal display control unit establishes a water content inversion formula based on the power attenuation of traveling wave antinodal points, and eliminates measurement errors caused by multiple reflection effects. The microwave water content measurement device based on the space traveling standing wave attenuation provided by the invention improves the measurement accuracy, makes a measurement result not affected by the material thickness and the bulk density, and can realize the fast, non-destructive measurement of the water content of granular materials such as grains, feeds, woods, gravels and the like.

Description

technical field [0001] The invention belongs to the technical field of microwave applications, and in particular relates to a microwave water content measurement device and a measurement method based on space traveling standing wave attenuation. Background technique [0002] In the process of industrial and agricultural production, moisture content has always been an important index for product quality evaluation. For example, in the links of grain storage, transportation, processing, etc., if the moisture content is too high, it will easily cause grain germination, mold, and it is not easy to store, while if it is too low, it will destroy the internal physical structure of the grain and reduce its nutritional value; Moisture content directly affects the molding strength of buildings; in the process of wood processing, in order to prevent bending or cracking of products, the range of moisture content needs to be strictly controlled. Therefore, realizing fast and high-precis...

AI Technical Summary

Problems solved by technology

[0005] The existing microwave free space transmission water content measurement technology requires the material thickness to have an attenuation of more than 10dB to reduce the multiple reflections of the microwave signal inside the sample. Accurate measurement cannot be completed when the sample thickness is thin or the water content is low.

At the same time, multiple reflections of the signal between the microwave antenna probe and the sample surface cannot be avoided. Microwave signals with the same frequency and opposite directions are superimposed in space to form traveling standing wave interference, which directly affects the measurement accuracy of microwave attenuation and phase change, and limits the microwave water content. Practical application of the measuring device

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