Developing an Online Measurement Device Based on Resistance Sensor for Measurement of Single Grain Moisture Content in Drying Process

Abstract

The online measurement of moisture content for grains is an essential technology to realize real-time tracking and control, improve drying quality and reduce energy consumption of the drying process. To improve the measurement accuracy and reliability of the dynamic measurement process as well as expand the application scope of the device, the present work constructed an experimental equipment for determining dynamic resistance characteristics of a single grain. The relations between moisture content and real-time resistance waveform were revealed, and an analytical calculation method of peak value and peak area of waveform was proposed, which correctly revealed the electrical measurement properties of grain. The results demonstrated that the gap width between the electrodes had large influence on the sensor’s performance. Moreover, an online measuring device was developed based on the experimental analysis and calculation method, and the test results in both lab and field for different grains showed that online real-time absolute measurement error are within ±0.5% in the varied moisture content (10–35%w.b.) and the temperature (−20–50 °C). The main results and the developed device might provide technical support for developing intelligent grain drying equipment.

Capacitive Online Corn Moisture Content Sensor Considering Porosity Distributions: Modeling, Design, and Experiments

“…The average initial moisture content was 27.9% w.b. measured using an air convection oven (Model DHG070B, Shanghai Anting Scientific Instrument Factory, Shanghai, China) according to the standard oven method [13]. The impurities and broken grains of corn to be dried were filtered through a filter screen and an air separator before entering the dryer, and the impurity content was less than 1%.…”

“…In recent years, for the moisture content measurement of agricultural products, researchers have developed a variety of static measurement instruments with high measurement accuracy based on optical [6,7], nuclear [8], hygrometric [9], and dielectric methods [10][11][12]. However, due to the difference in drying parameters, environmental conditions, material properties, and development costs, the most practical method is an electronic online measurement device based on the resistance and capacitance properties of materials [13,14]. Due to the shape of a corn kernel being flat or nearly spherical, the moisture content of different parts in a single kernel varies widely, and water diffusion occurs from the endosperm to the embryo during the drying process [15].…”

Energy and Exergy Analyses of a Combined Infrared Radiation-Counterflow Circulation (IRCC) Corn Dryer

“…The temperature data used in the experiment including inlet air (T ai ), outlet air (T ao ), outlet corn (T g ), ambient (T ∞ ), radiator (T r ) temperature and humidity data including inlet air (H ai ), outlet air (H ao ), ambient (H ∞ ) humidity were measured by the appropriate sensors, which were linked with the self-developed data acquisition system, as shown in Figure 3. The MC of the outlet corn were measured using the standard oven method [26]. According to the national standard GB 1353-2018 [33], the safe storage moisture content of corn is about 14% w.b.…”

“…2020, 10, x FOR PEER REVIEW 5 of 21 in Figure 3. The MC of the outlet corn were measured using the standard oven method [26].…”

Study of the efficiency of drying grass seeds for forage crops on a rotary dryer

“…And the aerodynamic properties of grass seeds do not allow the coolant to be supplied at a higher speed in order to avoid losses. These and other features complicate and complicate the drying process [3,[10][11][12].…”