Use of Plc as ICTS for Humidity Control in the Refrigeration Area of an Agricultural Industry of the Mexicali Valley, México

This work shows the need to apply information and communication technologies (ICTs) with a Programming Logic Controller (PLC) to control humidity by remote monitoring in the refrigeration process of an agricultural industry located in the Mexicali Valley of northwestern Mexico, where large amounts of orange are grown in this region of the country. This industry there were automated electronic devices (AEDs) for humidity control in the refrigeration area to prevent the deterioration of this agricultural product, only that the AEDs installed inside the evaluated company, did not operate properly due to the presence of outdoor atmospheric pollution (hydrogen sulfide (H2S)) and oxide sulfur (SO2)), and extreme climates in summer and winter (variations of temperature and relative humidity (RH))in this area of the country, that had an negative effect in indoors environments, and damaged their electrical connections. The principal climatic variables are the temperature and relative humidity (RH). The humidity in the refrigerated room for the orange keep its nutritional and physiological conditions, had to be between 45% and 55%. As AED, did not function properly, the climate inside the agricultural industry was not controlled, causing low and high humidity levels. With indexes below 30% humidity in the refrigerated room, oranges dehydrated and began to wilt, in addition to losing weight that was considered as unfit products for marketing. And at levels greater than 60% humidity, in this agricultural product microorganisms formed and caused rot, considered as a defective product and in both cases causing economic losses. The PLC was used with a wireless system and installed in an isolated room that only specialized personnel could enter if necessary. This was done in this way, to avoid deterioration of their electrical connections and that they did not operate as the AEDs and had adequate humidity control, to constantly maintain adequate humidity in the refrigerated room and avoid the generation of defective products. The research was made out from 2018 to 2019.