RFID Sensor: Measuring the Temperature and Humidity of Green Vegetables [Full Text]

"RFID sensors" track the temperature and humidity of leafy green vegetables in the supply chain, led by a group of scientists at California State Polytechnic University, research - planned for full launch in the first quarter of 2010 - hoping to determine when and what Under conditions, "high-risk" products begin to develop food-borne pathogenic infections.

The study will include at least four agricultural product packaging plants, as well as major retailers, truck companies and distribution centers. The research team used Sensor Wireless's Active Wireless Sensor (AWS) 2.4 GHz ZigBee RFID tag embedded with temperature and humidity sensors. The tag sends information to a GPS receiver (for tracking truck location and sending data via GPRS connection). The central receiving station,.

The study will focus on multi-leaf green vegetables because E. coli is common in such agricultural products. Since 1993, at least 25 outbreaks of E. coli have been traced to leafy green vegetables, mainly lettuce and spinach. At present, there is basically no trace of temperature and humidity in the commercial transportation of leafy vegetables, said Keith Vorst, associate professor and research chief investigator at California State Polytechnic University. For this reason, the research team is very interested in obtaining visible images of agricultural products under transportation and warehouse storage conditions.

E. coli is common in leafy green vegetables such as lettuce and spinach

Using AWS technology, researchers can receive status data on lettuce and spinach in real time, according to Waywire McNally, Chairman of Sensor Wireless - although the vast majority of data from the initial study was only studied during the final stages of the shipment.

When the East Coast, West Coast and Midwest containers loaded with green vegetables were loaded onto trucks, California State Polytechnic University will place AWS sensors in the containers. A total of 5 trucks were tracked in each region. Since the loading and unloading of goods at the distribution center (including the mixing of pallets for multiple regional products) will make the temperature and humidity tracking of the cargo environment more complicated, the researchers placed the sensors in the containers. Instead of on the pallet.

The sensor measures the temperature and humidity around the agricultural product in the truck every two minutes, and then sends the data to a Sensor Wireless Sensor Communication Interface (SCI) device that functions like an RFID reader. The SCI in turn sends data via GPRS signals, including location information, to the Sensor Wireless software on which the server is running. Whether the truck is on a loading platform or on a highway, the SCI sends data every two minutes as long as there is a honeycomb connection.

The Sensor Wireless software compiles the data and the researchers obtain the sensors and location information. If the temperature and humidity exceed a preset threshold, the software will send an alert to the California State Polytechnic designated contact point. The SCI sends messages every two minutes. Researchers receive 720 temperature and humidity readings sent by each sensor every 24 hours, depending on how many of the 15 trucks are at work, up to 450 at any time. Sensors send information.

Each packaging plant and distribution center will have a GPRS module installed, although Vorst states that he expects some parts of the supply chain to have no cellular connections. If an SCI cannot find the GPRS signal, it will store the sensor data until it enters another signal range. At retail stores, sensors are removed from the produce containers and reused for other goods, followed by the sale of lettuce and spinach to consumers.

At the same time, researchers will re-use temperature and humidity data to reconstruct the temperature and humidity conditions experienced by the vegetables during transportation. In a simulated experiment, a batch of mixed salad or other leafy vegetables will be planted in E. coli, allowing researchers to study the growth of pathogens.

Vorst hopes that this study can solve a problem: determine whether this technology can be used in the food industry to prevent food diseases. “The food industry must not allow the existence of foodborne pathogens, but it is clear that this situation has been happening. Some pathogens may occur in the supply chain, he said, people are currently understanding the environmental status of agricultural products in the supply chain Very little.

This is the first phase of the study. The first year of the study will include tracking temperature and humidity data on road vehicles and goods. The next year will be used for data analysis. Later, Vorst said that researchers will build wireless sensor technology at retail stores to track the temperature and humidity of products on the container or in the warehouse.

If the system works as expected, McNally claims that the food industry will use the Sensor Wireless solution to track the status of fresh foods. The price per SCI is $200, and the cost of acquiring sensor data every month is 40-60 USD.

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