Grain Silo & Grain Storage Temperature Monitoring

Stored grain is alive. It respires slowly, and so do the insects and moulds that live in it. When insects multiply or moisture collects in one part of a grain storage silo, that pocket heats up. The heat drives more moisture, which helps more mould and insects, and the hot spot spreads. By the time the grain smells musty or cakes, a large volume may already be damaged.

A rise of a few degrees at one sensor, compared with the others at the same depth, is usually the first measurable signal. That is why silo temperature monitoring at many points, recorded continuously and compared over weeks, is one of the most useful grain storage techniques available.

Safe storage depends on grain moisture and grain temperature together; drier, cooler grain keeps longer. The points below are general guidance, not a specification for any commodity. Follow the moisture and storage norms set by your buyer, FCI or state warehousing corporation for each grain.

A single probe cannot represent a silo holding thousands of tonnes. Silo operators usually hang temperature cables from the roof with sensing points at several depths, or push probes into bag stacks at different heights. The IBI-MTR8 and IBI-WTR8 read up to eight PT100 inputs, and the IBI-MTR4 reads four, each with 2-, 3- or 4-wire PT100 support, an accuracy of 0.5 °C and an OLED display. The IBI-OTR8 offline 8-channel logger suits temporary surveys or sites that only need periodic downloads.

Ideabytes IoT supplies the loggers and PT100 probes. Silo temperature cables themselves are usually third-party products; PT100-output cables can connect to our multi-channel loggers, so check the cable output type when you plan the system. The IBI-MT350 single-channel 4G logger with a PT100 probe suits a single monitoring point, such as a small bin or a dryer outlet.

In a bulk silo, temperature cables are usually hung from the roof so that sensing points sit at regular depths, with one cable near the centre and others between the centre and the wall in larger silos. The centre and the upper layers tend to heat first, while wall zones are where moisture from condensation collects. Record the depth of every sensing point so an alert tells the operator exactly where to look.

In bag stacks, probes pushed into the middle of the stack at low, middle and high levels give a useful picture of grain temperature. Add one ambient point per bay to compare grain with air. Protect probe leads from rodents and forklifts, and label each channel on the logger so readings stay traceable after restacking.

In flat warehouses and godowns, grain is stored in bag stacks rather than bulk silos, and the air around the stacks matters as much as the grain inside them. High humidity during the monsoon lets bags take up moisture; poor ventilation traps it. The IBI-A-TH485 RS485 temperature and humidity sensor can be placed at several positions in a warehouse and read through one IBI-CSC50RM 4G or IBI-CSC50R Wi-Fi MODBUS gateway, each handling up to 15 RS485 devices and up to 30 parameters.

Where a simpler setup is enough, a stand-alone IBI-MTH120 4G temperature and humidity logger per warehouse bay records ambient conditions and sends alerts. Probes pushed into selected stacks and connected to a PT100 multi-channel logger add grain temperature to the same dashboard.

Grain storage silos in India are spread across procurement areas in Punjab, Haryana, Madhya Pradesh, Uttar Pradesh and other states, often at rail sidings and rural mandis far from reliable broadband. The key stakeholders include the Food Corporation of India, the Central and State Warehousing Corporations, private silo operators under public-private partnership projects, and warehouses registered with the Warehousing Development and Regulatory Authority (WDRA).

For these sites, 4G loggers and the IBI-CSC50RM gateway with a built-in M2M SIM send data without any site network. Loggers keep recording through power cuts and upload when the connection returns, so a regional manager can see every silo in one place.

Alerts can be set on absolute grain temperature and on a rise over a defined period, so a slow-developing hot spot is flagged early. SMS and app notifications go to the site in-charge first, then to the regional manager if the alert is not acknowledged. Every alert and response is logged.

Weekly trend reports show each sensing point over time, which helps plan aeration, fumigation and turning, and gives depositors and lenders a condition history for the stock. In automated grain storage projects, the MODBUS gateway can also bring RS485 sensor readings into one system alongside the loggers. Ideabytes IoT is registered on GeM, manufactures in India and provides 21 CFR Part 11 compliant reports.