Stored grain is alive. It respires. It generates heat. It exchanges moisture with the surrounding air. Insects and microorganisms within the grain mass generate additional heat and CO2 as they metabolize. Left unmanaged, these biological processes can degrade grain quality from Grade 1 to unmarketable in weeks.
The standard of care for stored grain is temperature cable monitoring with periodic manual checks — typically once per week for the temperature cable readings. That weekly check catches the problem when the hot spot has been developing for 3–7 days. At grain storage densities and value levels, 3–7 days of undetected anomaly can represent significant quality and quantity loss.
Continuous IoT monitoring with IoT SimpleLink changes the detection window from a week to hours.
What Grain Storage Monitoring Measures
Temperature Cables and Profile Monitoring
A temperature cable runs vertically through a bin or silo from the roof to the floor, with temperature sensors at defined intervals — typically every 6–10 feet. A bin 60 feet tall might have 7–10 sensors per cable, and multiple cables per bin (typically 3–5 cables per bin for even spatial coverage).
This sensor array creates a three-dimensional temperature profile of the grain mass: hot spots appear as elevated temperature readings at specific positions on specific cables.
Normal grain temperature for safe storage:
- Corn stored for 6+ months: 35–40°F target in winter, below 60°F acceptable in summer
- Soybeans: below 50°F for long-term storage
- Wheat: below 40°F for quality preservation
Alert thresholds:
- Warm spot: 5°F above the baseline average temperature for that depth and position
- Hot spot: 90°F absolute, or 15°F above baseline — immediate action required
- Critical: 110°F+ — grain quality at risk, emergency aeration or movement required
IoT SimpleLink-connected temperature cable interface units read each sensor on the cable at 15-minute intervals and transmit the full profile to VX-Olympus. The grain manager sees a color-coded temperature profile for every bin, updated continuously.
Moisture Monitoring
Grain moisture content at harvest determines whether grain is safe for long-term storage:
- Corn: ≤14% for long-term storage, ≤13% for summer storage
- Soybeans: ≤13%
- Wheat: ≤13.5%
Grain stored above safe moisture content generates heat from microbial respiration and develops mold and mycotoxins. High-moisture grain in storage is a race against time.
IoT-connected moisture sensors monitor:
Bin headspace humidity: The air in the headspace above the grain reflects the equilibrium moisture condition of the top grain layer. Rising headspace humidity with stable outside air conditions indicates moisture migration within the grain mass — a warning that moisture is redistributing from lower to upper layers.
In-grain moisture probes: Point-in-grain moisture sensors provide direct readings at specific depths. Combined with temperature profile data, they identify zones where temperature and moisture conditions create quality risk.
Intake moisture monitoring: Moisture sensors at bin load-in points verify that incoming grain is within safe storage parameters before it enters the bin — a quality gate that prevents bringing high-moisture grain into the storage system.
Aeration System Integration
Aeration fans force ambient air through the grain mass to equalize temperature, remove stored heat, and manage moisture. Aeration is the primary tool for correcting temperature and moisture problems in stored grain.
VX-Olympus integrates with aeration fan controls via relay outputs and Modbus interfaces to enable automated aeration management:
Condition-triggered aeration: When temperature profile shows a developing hot spot, VX-Olympus activates the aeration fan for the affected bin automatically — without requiring manual intervention. The fan runs until the temperature profile normalizes, then shuts off.
Optimal aeration windows: Aeration is most effective when outside air is cooler than the grain mass and at the target humidity level. VX-Olympus evaluates outside air temperature and humidity and runs aeration fans only during favorable conditions — maximizing cooling effectiveness and minimizing energy use.
Aeration run logging: Every aeration run — start time, stop time, duration, conditions at start and end — is logged in VX-Olympus. This provides documentation for grain quality records and helps optimize future aeration scheduling.
Multi-Bin Dashboard
A grain operation with 12 bins has a grid view in VX-Olympus: each bin as a color-coded square:
- Green: All temperatures within normal range, no anomalies
- Amber: At least one sensor reading in the watch zone — investigate
- Red: Hot spot threshold breached — action required
Click any bin to see the full temperature profile: a grid showing temperature at each cable/depth position, with the hottest readings highlighted. Historical trend for any sensor position visible in the detail view.
Integration With Grain Elevator and Merchandising Systems
For commercial grain handlers operating elevators and storage facilities, VX-Olympus integrates with grain management software:
- Inventory management: Bin level sensors (ultrasonic or cable-type) provide real-time bushel inventory alongside quality data
- Quality record export: Temperature and moisture history for each lot is exportable for grain merchandising documentation — supporting quality representations to buyers
- Lot tracking: When grain is moved between bins, the grain identity and quality record follows it in VX-Olympus
The LoRaWAN Advantage for Grain Storage
Grain bins are often remote from power infrastructure. A LoRaWAN gateway at the elevator — a natural high point — covers all bins on the property without running power or network to each bin.
Temperature cable interface units running on battery report to the gateway without any infrastructure at the bin. Aeration fan control integration does require power at the fan controller, but most grain operations have power to the fan systems already.
The IoT network for a 12-bin grain storage facility with a central elevator typically requires:
- 1 LoRaWAN gateway at the elevator
- 1 IoT interface unit per bin (battery or powered)
- Temperature cable connection at each unit
- No new wiring between bins and the central system
Managed through IoT SimpleLink, all sensors and interface units are visible centrally. A firmware update to all 12 units deploys through one OTA campaign.
The Outcome
Grain storage quality is preserved in the detection gap. The smaller that gap, the less grain is lost to problems that were already starting. Continuous IoT monitoring with IoT SimpleLink makes that gap hours instead of days.
Talk to our team about a grain storage monitoring deployment for your storage capacity and bin count.