IoT (the Internet of Things) connects physical devices, such as temperature sensors, to a central system that stores and analyses what they measure. In food safety that means a sensor in every fridge, freezer, cold room and vehicle, reporting every few minutes to one platform that raises an alarm when a reading goes out of range.
The point isn't the technology. It's that the hours between manual checks stop being blind spots, and the record an auditor asks for builds itself.
How an IoT monitoring system fits together
A JTF system has three parts, and each has one job.
- Node+ and Eye sensorsSensorsEvery few minutes
- Measure temperature, humidity or door state
- Log locally and send readings by radio
- Link+ gatewaysGatewaysContinuously
- Receive readings across the site
- Send them securely to the cloud
- SematicsPlatformAround the clock
- Store every reading
- Check limits and raise alarms
- Produce reports and audit trails
- Your teamPeopleWhen it matters
- Acknowledge the alarm
- Act and record what was done
The three parts of a wireless monitoring system, and the person at the end of it.
Node+ sensors measure temperature, humidity or door state. Link+ gateways carry the readings to the Sematics platform, which stores them, checks them against your limits and alarms. Sematics processes 11 million+ temperature readings a day across all the sites it monitors.
Why manual checks fall short
Paper logs and basic standalone thermometers have the same weaknesses:
- They only capture the moment someone looks.
- They depend on someone remembering, and writing it down correctly.
- They don't tell anyone when a unit fails overnight.
- They can't show a manager what is happening across several sites.
Those gaps are where temperature excursions go unnoticed, and where audit findings come from.
What smart sensors add
Accurate, calibrated readings
A reading is only evidence if the sensor is known to be accurate. Node+ sensors are specified for food and medicines storage (see the Node+ Digital specifications), and we offer calibration for every sensor we supply: traceable to national standards as standard, or UKAS accredited where you need it (temperature in our own UKAS accredited calibration laboratory No. 10723, accredited to ISO/IEC 17025; other parameters through accredited partners). Certificates sit on the platform against each sensor's serial number.
Long-range wireless
LoRaWAN radio reaches through walls and across large sites, including into walk-in freezers, without cable runs. Read why LoRaWAN suits long-range monitoring.
Low power, long battery life
The sensors are designed to run for years on one battery at normal logging intervals, so maintenance visits are rare and nothing has to be wired back to a mains supply. The exact figure depends on how often the sensor logs; the product pages give it.
Alarms that reach a person
When a reading crosses its limit, Sematics alerts by text, phone call, email and app, and escalates if nobody acknowledges. See alarms and reporting.
One record, in the cloud
Every reading is stored securely and can be viewed from anywhere by authorised users, with history, reports and a full audit trail.
Alarm raised as the reading passes −18 °C
Illustrative. A manual check at 07:00 would find the problem; a sensor alarms when it starts.
What to check before you choose sensors
Most food businesses compare systems on price per sensor. The questions that matter more at audit and at 02:00 are these:
- Range and accuracy. Does the sensor cover your coldest freezer and your warmest ambient store, with an accuracy suited to your limits?
- Calibration. Who calibrates it, under what accreditation, and how are certificates matched to each sensor?
- Local logging. If the connection drops, does the sensor keep its readings and send them later, so the record has no gaps?
- Alarms. Can alarms escalate to a second person, and is each acknowledgement and action recorded?
- Support. Who installs it, who answers when it goes wrong, and how quickly?
Our guide to choosing a temperature monitoring system goes through each of these in more detail.
Beyond compliance
Monitoring helps you evidence temperature control, but the data is useful well beyond the audit:
- Less food waste, because failures are caught before stock is lost.
- Better energy use, because you can see which units work hardest. See cutting cold store energy costs.
- Maintenance planned from data rather than call-outs.
- Records that reassure customers and auditors.
- Monitoring that grows with you, from one site to many.
Where connected food safety is heading
The direction is clear even if the pace varies: more use of trend data to spot a failing unit early, more reporting produced automatically rather than by hand, monitoring data linked to wider supply chain systems through integrations, and more attention to energy and sustainability.
Smart sensors are no longer a nice extra. For most food businesses with chilled or frozen stock, they are the simplest way to know what is happening in every unit, and to prove it.
Questions people ask
Can JTF calibrate third-party sensors?
Yes, for compatible LoRaWAN sensors on the Sematics platform. Temperature calibration is done in our own UKAS accredited calibration laboratory No. 10723 (accredited to ISO/IEC 17025); other parameters go through accredited partners.
Why does calibration matter for day-to-day operations?
A sensor that reads wrong either misses a real problem or raises false alarms that people learn to ignore. Regular calibration keeps readings trustworthy, so alarms get acted on and the records stand up at audit.
What is ISO/IEC 17025 accredited calibration?
It is calibration done by a laboratory that a national body, UKAS in the UK, has assessed against ISO/IEC 17025 for competence and traceability. Labs are accredited, not certified, and each accreditation has a defined scope: ours, UKAS accredited calibration laboratory No. 10723, covers temperature.
Do wireless sensors work inside walk-in freezers?
Usually, yes. LoRaWAN radio passes through cold room walls better than most wireless types, and a site survey shows where gateways need to go before installation.
