▼Measurement indicators
Moisture content (%).
▼Application areas
Paper, cloth, board and other surface materials.
▼Main components
The microwave moisture sensor consists of two parts: the auxiliary resonant cavity and the main resonant cavity.
The main resonant cavity mainly includes: sensor box, microwave transmission source, antenna, resonant cavity, microwave receiver, control sampling circuit board, temperature measurement circuit and sensor, microwave window film, etc.
The auxiliary resonant cavity mainly includes: a sensor box, a resonant cavity, a temperature measurement circuit and a sensor, a microwave window film, etc.
▼Measurement principle
Microwave is a high-frequency electromagnetic wave. The attenuation and phase change caused by microwave transmission through the medium are mainly determined by the dielectric constant and dielectric loss tangent of the medium. Water is a polar molecule. The dielectric constant and dielectric loss tangent of water are much higher than those of general media. Generally, the dielectric constant and loss tangent of water-containing media are mainly determined by its moisture content. The main resonant cavity and the auxiliary resonant cavity form a closed-loop resonant cavity. The measured medium passes through the gap between the main and auxiliary resonant cavities. Microwaves are emitted from the microwave emission source of the main resonant cavity and enter the auxiliary resonant cavity through the measured medium. The microwave amplitude and phase change with the different moisture content of the measured medium. The microwave receiver on the main resonant cavity receives the microwave signal. According to the change in the attenuation and phase shift of microwave power, a mathematical model is established under the measurement of the change in multiple samples with different moisture contents, and the moisture content in the material can be calculated. Moisture content = moisture content/quantification × 100%.
▼Technical features
◆ Microwaves completely penetrate the process material, and the moisture on the surface and inside of the object being measured can be accurately measured;
◆ Wide moisture measurement range;
◆ The color and surface structure of the material being measured will not affect the measurement results.
◆ Suitable for non-contact online measurement.
◆ Sensor temperature compensation, self-cleaning and dust-proof measuring window.
▼Performance indicators
