Short answer
In cold chain tracking, one or more temperature sensors placed inside the cargo box are connected to the vehicle tracking device. The device records the temperature along with the location at set intervals; when the temperature goes outside the set range, or the cargo door is opened on the road, it sends an instant alert to the manager. The records turn into a report showing at what temperature the product was carried during delivery.
Where do cold chain problems occur?
Products such as dairy, meat, frozen food, vaccines, and medicine must be transported within a certain temperature range. Even a short time outside this range can make the product unusable. The problem often happens in the middle of the road, at a moment the driver does not notice.
The most common causes are: the refrigeration unit breaking down or the driver turning off the unit to save fuel, the door staying open for a long time at delivery points, the cargo box not being cooled enough before loading, and long waits in the sun in summer heat. A delivery vehicle going from Şanlıurfa to Gaziantep, Mardin, or Diyarbakır can see the box temperature rise even from a door left open for a few minutes at summer noon.
In a vehicle with no temperature tracking, these problems come to light only after the product is delivered, through the customer's complaint.
How does the system work?
The tracking device installed in the vehicle sends location information to the server over the mobile network. In a cold chain application, temperature sensors inside the cargo box are connected to the device. The sensors can be wired probes or can send data to the device wirelessly.
The device reads the temperature at set intervals and records it together with the location. From the web panel or the phone app, the manager sees each vehicle's live location and cargo box temperature. In the historical report, how the temperature changed during a particular delivery can also be followed as a graph.
A door sensor fitted to the cargo box door records where and for how long the door was left open. Whether the refrigeration unit is running can also be connected to the device as an input.
The reading interval is chosen according to the sensitivity of the product. Very infrequent readings can miss short temperature spikes; very frequent readings increase data and battery use. For sensitive products such as vaccines and medicine, more frequent readings may be needed, while for fresh fruit and vegetables less frequent readings may be enough.
How many sensors, and where?
The temperature is not the same at every point inside the box. The spot near the refrigeration unit's air outlet is the coldest, and the door side and the ceiling of the box are the warmest points. If a single sensor will be used, it is usually placed at the point where the product is most at risk, that is, on the door side or somewhere near the middle of the box.
Long cargo boxes and vehicles with more than one compartment need a separate sensor for each compartment. For example, if frozen products are carried in one compartment and fresh products in another, both compartments need to be monitored separately and have separate thresholds defined.
Placing the sensor directly in the cooler's air stream shows a low temperature even when the rest of the box warms up. Placing it right next to the door can produce a brief false alarm every time the door opens. The right place is determined by the structure of the box and the loading layout.
Expert note: Compare the sensors against a reliable reference thermometer at regular intervals. If the records will be used in an inspection or in a dispute with a customer, you need to be able to show that the sensor measures correctly.
- 1Define the product's temperature range
- 2Place sensors in the cargo box
- 3Connect the door sensor
- 4Define the threshold and the delay
- 5Choose who will receive alerts
- 6Check the report regularly
Alerts: when, and to whom?
The real value of temperature tracking is that it warns you while the problem is happening. For this, a lower and an upper threshold are defined for each product group. When the temperature goes outside this range, the system sends a notification to the manager and, if needed, to the driver.
To prevent meaningless alerts from short door openings, a delay time is defined: an alert comes only if the temperature stays outside the threshold for a certain time. This time is chosen according to the sensitivity of the product.
The main alerts that can be used are:
Who the alert goes to is at least as important as the threshold. If it is not clear who will see a temperature alert that arrives at midnight, the system does no more than keep records. A person on duty should be assigned according to the shift schedule, and the alert should be made to go to that person.
- Cargo box temperature exceeded the upper threshold
- Cargo box temperature dropped below the lower threshold (risk of freezing)
- Cargo box door opened outside a delivery point
- Door stayed open longer than the set time
- Refrigeration unit shut off while the vehicle was moving
- No data coming from the sensor
Report and records
The cold chain report shows the cargo box temperature, door openings, and location from the start to the end of every trip in a single document. This report can be given to the customer with the delivery and used in an internal audit or in a review after a complaint.
For the distribution of medicine and some food products, keeping temperature records and storing them for a certain period may be required by regulation or by the customer's specification. Which records are kept and for how long varies by sector and product; check the relevant regulation and your customer's requirements.
In addition to storing the records on the server, it is important that the device also keeps the data in its own memory. While the vehicle is outside mobile coverage, measurements must not be lost, and they must be transferred to the server once the connection returns.
Benefits that come with vehicle tracking
The device installed for temperature tracking also brings the other features of the vehicle tracking system. Route, stop duration, speed, and idling reports make delivery planning easier. How long the vehicle waits at a delivery point is assessed together with how long the door stays open there.
Running the refrigeration unit at idle for a long time increases fuel consumption. Idling and stop reports show where unnecessary waiting happens. Looking at these reports together with the driver reduces both fuel use and product risk.
Driver behavior and location data count as personal data. Drivers should be informed about the system, and who will access the data should be determined.
Installation and selection
When choosing a device, ask about the number of temperature sensor inputs, the door and cooler inputs, the capacity to store data outside the coverage area, and whether the reports can be exported. When sensor cables are passed through the cargo box wall, the insulation must not be damaged and watertight sealing must be ensured.
Desa Bilişim installs vehicle tracking and temperature monitoring for food and medicine distribution fleets in Şanlıurfa. We can look at your vehicles and the products you carry and prepare a plan for the number of sensors and the alert setup.
Frequently asked
If I already have a vehicle tracking device, can a temperature sensor be added?
It can be added if the device has a sensor input or wireless sensor support. Many basic tracking devices do not have this input. In that case, you need to install a device suited to temperature tracking.
Is the temperature record lost outside the coverage area?
A good device stores the measurements in its own memory when there is no mobile connection and sends them to the server when the connection returns. Ask about this feature and the memory capacity when choosing a device.
Will I know if the driver turns off the refrigeration unit?
If the operating signal of the refrigeration unit is connected to the device, you can get an alert the moment the unit shuts off while the vehicle is moving. If it is not connected, you notice it indirectly through the rise in temperature.
Keep your cargo box temperature in view on the road too
Let us see your vehicles and the products you carry, and prepare a written quote for temperature tracking.
