1. Direct drying method

Direct drying method: según norma ASAE, poner la muestra en el horno, guárdalo en el horno durante 19 horas a 130 ℃; medir la pérdida de peso, es decir., contenido de humedad.

2. Capacitance method

Capacitance method: La constante eléctrica de la humedad es mucho mayor que las constantes eléctricas de otros componentes del grano., El cambio en el contenido de humedad provocará inevitablemente el cambio de capacitancia.. Probando el cambio de capacitancia correspondiente al cambio de humedad de la muestra., Se puede probar el contenido de humedad del grano..

3. Infra-red heating drying method

Infra-red heating drying method uses infra-red light to heat the sample and remove the moisture, so as to test the moisture content. The main influencing factors are temperature and heating time. Online testing is not applicable for this method.

4. Microwave heating method

Microwave heating method uses the 2450MHz or 915MHz ultrahigh frequency microwave produced by microwave oven’s magnetron to oscillate the water molecules rapidly in order to make the molecules impact and rub each other and then remove the moisture in grain.

5. Ray method

Near infrared reflectance spectroscopy (NIRS) was first used in grain moisture testing in 1964. As different molecules have different features of absorption for near infra red lights of different wave lengths, when near infra red light (wave length 1940nm) is exposed to sample, light intensity of diffuse reflection is related to sample’s component content, in conformation with Lambert-Bill Law.

6. Micro wave absorption method

Micro wave absorption method started from 1840s. Moisture is tested indirectly by inspecting the absorption of micro wave energy by moisture or the change of parameters along with moisture like micro wave cavity resonant frequency and phase position.