The four layers
| Layer | Component | Job |
|---|---|---|
| Sensing | Probe cable with nodes at fixed depths | Temperature and interstitial humidity through the full grain column |
| Edge | Silo controller | Polls the cables, timestamps readings, buffers them, drives aeration relays |
| Transport | LoRa gateway | Collects from every controller on site and backhauls over Wi-Fi, Ethernet or cellular |
| Platform | GrainHero cloud | History, thresholds, spoilage scoring, alerts and reports |
Sensor placement
Coverage, not sensor count, is what determines whether a hot spot is detected. Grain conducts heat poorly, so a pocket more than roughly a metre from the nearest node can develop without moving that node's reading much.
- One cable at the centre line, where fines concentrate and airflow is weakest.
- Additional cables on a ring at roughly two-thirds of the radius, one per 6-8 metres of diameter.
- Nodes every 1.5-2 metres of depth, with one node in the headspace.
- Extra attention near the fill point and the roof, the two zones most exposed to condensation and moisture migration.
| Structure | Cables | Nodes per cable |
|---|---|---|
| 6 m bin | 1-2 | 4-6 |
| 12 m flat-bottom bin | 3-5 | 8-12 |
| 18 m concrete silo | 5-7 | 12-16 |
| Flat store / warehouse pile | Grid on 8-10 m spacing | 3-5 |
Working without reliable internet
Most storage sites are not well connected, so the system is designed to keep measuring regardless. Controllers hold readings in local storage and the gateway retries the backhaul continuously. When the link returns, buffered readings are uploaded with their original timestamps, so the trend line stays continuous rather than showing a gap. Local threshold rules keep working during the outage, including aeration control, so a hot spot is still acted on even when nothing can reach the cloud.
Installation and tracking
Hardware is ordered through your account. Each order carries the structures it covers, and once scheduled it shows the assigned technician, the install date and the city and site. After commissioning, every device stays linked to the silo it was installed in, so the same record answers both "where is my order" and "which sensor is reporting this reading". Managers see the full trail from their installation orders page.
Frequently asked questions
What is a silo monitoring system?
A silo monitoring system is the hardware layer that measures conditions inside a storage structure and delivers them to software. It normally consists of suspended probe cables carrying temperature and humidity sensors at fixed depths, a controller at the silo, a radio gateway for the site, and a cloud service that stores and interprets the readings.
How many sensors does one silo need?
Coverage depends on diameter and height rather than a fixed count. The practical rule is one probe cable per 6-8 metres of diameter plus one at the centre, with sensor nodes every 1.5-2 metres of grain depth. A 12 metre flat-bottom bin typically ends up with three to five cables.
Can it be retrofitted to an existing silo?
Yes. Probe cables are suspended from roof anchors and no structural modification is required for most steel and concrete silos. Flat stores and warehouse piles use floor-anchored or wall-mounted probes instead.
What connectivity does it use?
Sensor-to-gateway links use LoRa, which reaches several kilometres line-of-sight and passes through farm infrastructure well. The gateway backhauls over Wi-Fi, Ethernet or cellular, whichever the site has. Readings are buffered locally when the backhaul drops and backfilled on reconnection.
How is it powered?
Controllers run on mains power where available, with a solar and battery option for remote structures. Sensor nodes draw from the probe cable rather than individual batteries, so there are no cells to replace inside the grain mass.
Who installs it?
GrainHero dispatches an assigned technician for the install. The order, the technician, the scheduled date and the per-silo sensor placement are all visible in your account, and the same record tracks the device afterwards.