IoT sensors on a conveyor: what to monitor
Which conveyor parameters to monitor with IoT sensors: vibration, temperature, rpm. How to integrate with SCADA and spot a fault before failure.
An IoT sensor on a conveyor is a small device that measures a physical parameter of a component and passes it to a system. The point is not the technology itself but the fact that the data lets you see a fault a week or two before failure. Let us break down which parameters are worth monitoring and how to integrate sensors into an existing line without rebuilding it.
What conveyor monitoring delivers
Without sensors, a mechanic learns of a problem from its consequences: a hum, overheating, a stoppage. By that point the component is already worn and the line may be standing. IoT monitoring shifts the reaction point: a deviation is visible on a chart long before it can be heard by ear.
On our projects it works simply — the sensor sends a value every minute, the system compares it with the norm. When the trend creeps up, the mechanic gets an alert and schedules the repair in a convenient window rather than reacting to a breakdown.
The economics are easy to count. A sudden failure of a drive-drum bearing at the height of the season means 6–8 hours of downtime for disassembly, centring and replacement, plus spoiled product in the unfinished cycle. The same bearing, caught two weeks earlier at an early stage, is replaced in a scheduled maintenance window with no loss of production time at all. It is this difference, not the “trendiness” of the technology, that makes sensors pay off.
Vibration: the key parameter
Vibration is the most informative signal of the condition of rotating components. A rise in amplitude almost always means one of three things: bearing wear, drum imbalance or loose fastening. The sensor is fitted on the housing of the bearing unit of the drive and tension drums — always rigidly, on a threaded mount or magnet, because a glued seat distorts the spectrum at high frequencies.
What matters is not the absolute figure but the dynamics. We record the baseline vibration level right after installation and calibration, then track the deviation from that baseline. A jump of 40–50% is reason to inspect the component. For reference: under ISO 10816 the overall vibration level of a healthy drive unit of a food conveyor stays within 1.8–2.8 mm/s RMS; going beyond 4.5 mm/s is already a zone where bearing life drops several times over. Modern accelerometers let you look not only at the overall level but at the spectrum: a peak at the rotation frequency means imbalance, while a peak at the bearing outer-race defect frequency points specifically to its wear. This turns diagnostics from “something hums” into a precise fault address.
Temperature and rpm
Bearing temperature is the second most important parameter. Normal heating is 15–20 °C above ambient. An excess points to a lack of lubricant, over-tightening or cage breakdown. A temperature sensor is cheap and is placed next to the vibration one.
Drum rpm monitoring detects belt slippage. If the drum turns while the belt lags, the rpm counter will show a mismatch with the set speed. This is an early sign of insufficient tension or a contaminated drive drum.
Parameters to monitor
| Parameter | Norm | Sensor | Alarm |
|---|---|---|---|
| Bearing vibration | baseline level | accelerometer | +40% over baseline |
| Component temperature | +15…20 °C over ambient | thermocouple / NTC | over +35 °C |
| Drum rpm | set speed | inductive / Hall | deviation over 5% |
| Gear motor current | rated | current transformer | +15% over norm |
| Belt tension | calculated | load cell | out of range |
How to integrate sensors with SCADA
Integration does not require replacing all the equipment. The sequence is typical:
- Fit sensors on critical components — drive drum, tension drum, gear motor.
- Connect them to a hub or line controller via a wired or wireless channel.
- Set alarm thresholds for the specific component, not by a generic table.
- Output the data to the operator panel and a history log.
- Set up alerts to the mechanic — on screen, by email or messenger.
Engineer’s tip. Wireless sensors are convenient to install, but check the battery life — in a humid washing workshop it drains faster. For continuously loaded components we more often fit wired power so as not to find a “dead” sensor at the worst moment.
Wired or wireless connection
The choice of data channel is a separate engineering decision that the reliability of the whole system depends on. Wireless sensors on LoRaWAN, Zigbee or Bluetooth LE are installed in minutes and need no cable run across the workshop — ideal for upgrading an operating line. The trade-off is a limited battery life (usually 1–3 years) and the risk of packet loss in a workshop full of steel structures and frequency converters that create radio interference.
Wired sensors on industrial interfaces — 4–20 mA, RS-485/Modbus, IO-Link — give a stable signal with no battery service and are powered from the line. We fit these on critical, continuously loaded components where a “dead” sensor is unacceptable. In practice, one line combines both approaches: wired on drive drums, wireless on less critical idlers. The key point is that the sensor enclosure protection rating must be no lower than IP67 for washing zones, otherwise water gets into the electronics on the very first sanitary cycle.
Common mistakes when fitting monitoring
On other people’s projects we regularly see the same miscalculations. The first is a single alarm threshold for all components “by a table”. Every bearing has its own normal level, and an averaged threshold gives either false alarms or missed failures. The second is installing sensors and not assigning anyone responsible for looking at the charts daily: data with no reaction is useless. The third is ignoring the quality of the sensor mounting itself: play in an accelerometer mount distorts readings more than a real component defect. The fourth is forgetting the conveyor itself for the sake of the electronics: no sensors will save a line whose belt tension has not been adjusted for years.
What it costs and who needs it
Full monitoring of a small line is a few sets of sensors and a simple controller. The payback consists of avoided emergency downtime: one lost day in the season is usually costlier than the whole set of sensors. For lines with a seasonal peak, monitoring is especially justified — there the cost of downtime is highest. We allow for sensor mounting points back at the design stage of conveyors and transporters so as not to drill finished components later. Related material under the tag conveyor.
Conclusion
IoT sensors on a conveyor pay off not through the technology but through avoided downtime. The key parameters are vibration, temperature, rpm and current. It is worth starting with the most critical components and a simple controller, not a full SCADA. If you want to equip a line with monitoring, get in touch — we will select a sensor set for your components and budget.
