This presentation on wireless sensors for management of stored grain was given at the 2nd All Africa Post-Harvest Congress & Exhibition in Addis Ababa. The focus of the presentation was on coming to an understanding about the performance of wireless sensors for quality monitoring and management of stored grain. The research was undertaken in Iowa (USA) and the wireless sensors monitored maize (corn). As part of the research, the wireless sensors were also compared to the deployment of cable sensors, as well as tested for quality, accuracy, and recoverability. The lead researchers from Iowa State University, who prepared the presentation, are making it available via the Consortium for Innovation in Post-Harvest Loss and Food Waste Reduction SlideShare account. Iowa State University is a member of the Consortium.

1. Wireless Sensors for Quality Monitoring and
Management of Stored Grain Inventories
Guy Roger Aby (M.S. Student)
Dr. Dirk E. Maier
2nd All Africa Postharvest Congress and Exhibition
September 17-20, 2019
Africa Union Commission Headquarters, Addis Ababa, Ethiopia

2. Why monitor to manage stored grain?
• Numerous risks
• Molds and mycotoxins
• Insects
• Marketing
• Harvest season
Agricultural and Biosystems Engineering

3. Grain Storage Monitoring System
Temperature and moisture cables
• Advantages:
Accurate, last longer
• Disadvantages:
Interference
Structural Integrity
Cost
3
Agricultural and Biosystems Engineering

4. Options for Grain Monitoring System
Wireless sensors
• Advantages:
No interference with other equipment
Cheaper and fan control
No structural issues
• Disadvantages:
Might be broken
Shorter battery life
Agricultural and Biosystems Engineering

5. Objective:
• Compare the effectiveness of the wireless sensor
technology against a conventional cable-based sensor
system by monitoring temperature and relative humidity
in stored grain mass.
• Cable sensors vs GAC 2500 official moisture meter
• Wireless sensors vs Cable sensors
• Wireless sensors vs Cable sensors vs Vaisala high
accuracy sensor
• Wireless sensors recapture rate
Agricultural and Biosystems Engineering

6. Experiment 1:
Grain samples probed at 18 OPI cable sensors locations
within the grain mass and measured with GAC 2500
Results
18 EMC values obtained with GAC 2500 are statistically the same as the
EMC values generated by 18 OPI sensors
Agricultural and Biosystems Engineering

7. Experiment 2:
14 wireless and OPI sensors in the grain mass
Agricultural and Biosystems Engineering

8. Agricultural and Biosystems Engineering

9. Experiment 3:
4 wireless sensors, OPI cable sensors, and the Vaisala
sensor in the grain mass one step at a time
Agricultural and Biosystems Engineering

10. Experiment 4: Wireless sensors recapture
Agricultural and Biosystems Engineering

11. Wireless sensors recapture
• First trial
• 44 placed in the bin, 44 recaptured
• Second trial
• 15 placed in the bin, 15 recaptured
• Third trial
• 20 placed in the bin, 20 recaptured
• Fourth trial
• 25 placed in the bin, 25 recaptured
Results: 100% recapture rate
Agricultural and Biosystems Engineering

12. Conclusions
• Wireless sensor technology effectively monitors
temperature and relative humidity in stored grain
mass (silo, bag)
• Measured temperatures and relative humidity values were
as accurate as those measured with
• GAC 2500 official moisture meter
• conventional cable-based sensor system
• high-accuracy T/RH Vaisala high-accuracy probe
• Wireless sensors were successfully recaptured
during unloading of the grain
• 100% of wireless sensors were screened out without
impeding unloading capacity
Agricultural and Biosystems Engineering

13. Acknowledgement
• This research is supported with funding provided by
the NC-213 The Andersons Research Grant
Program and a National Science Foundation SBIR
project subcontract from Amber Agriculture
• Authors are grateful to staff of the ISU Agricultural
Engineering and Agronomy Research Farm for their
assistance with this project
Agricultural and Biosystems Engineering