Cold Chain and ‘Controlled Room Temperature’ (CRT) require complex logistics in which adding sensors to monitor asset condition provides great benefits.
We all have gotten used to extremely fast deliveries on all types of goods, from a small gadget to the latest Smart TV. You can have them at home the day after ordering without problems.
However, there are products that require more specific shipping conditions for the products to have any value after the shipping. One of the most evident cases are perishable foods and pharmaceuticals, where the goods need to be transported under specific temperature conditions to be healthy for the user.
The term cold chain is typically associated with the 2°C to 8°C while recently the term ‘Controlled Room Temperature’ is gaining more visibility. This is due to many products requiring temperature control in very different temperature ranges.
In both cold chain and CRT, food and drugs are spoiled if the correct ranges are not guaranteed as the products can potentially harm end users taking them. Temperature control is a big part of the regulatory compliance these kind of goods have to adhere to.
RFID + sensors: how do they help?
RFID has been used in logistics for quite a long time now. Being able to uniquely identify containers, pallets or even at item level provide a set of advantages in terms of tracking and tracing items.
This can also be done by barcodes of course but RFID brings up advantages in terms of faster readings, decreased human intervention, not requiring line of sight, etc. You will find lots of literature about RFID vs. barcodes just doing a quick search in google.
However, sensors involve a different concept in logistics. While they are of little value for tracking, they are so important for cold chain and CRT logistics that they have even become mandatory in some cases.
A complete log of the temperature conditions from manufacturing to delivery of drugs lets the end user know if the products are healthy to take. Same is applied to perishable foods: knowing the temperature conditions over time will allow the retailer to reduce spoilage by managing shelf life of goods according to objective data.
Using RFID + sensors on cold chain and CRT logistics helps improve supply chain and clarifies responsibilities over the assets if anything goes wrong – even allowing for more accurate insurance policies.
Technology approaches to cold chain and CRT monitoring
There are multiple approaches to cold chain and CRT monitoring. You don’t need to implement a wireless solution – while it is true that it provides great advantages too…
- Wired solutions. These solutions rely on a battery supply chain to power up sensors and log data over time. No data transfer is possible until the device is connected to a PC or similar to download the information – typically via USB, Ethernet or similar connections.
- Wireless solutions. While also dependent in battery supply for sensors and data logging, data transfer is possible at different supply chain locations. This allows for cargo evaluation at different points and users can implement corrective actions if needed.
Briefly, there are different types of wireless solutions. We will discuss them over future post but here are the main differences:
- Active solutions. These include devices with WiFi, Bluetooth or similar communication. They allow for long range communication at the cost of a much shorter battery life. Can only be used for logistics of short periods of time and battery changes usually involve an ever increasing maintenance cost.
- Battery assisted passive solutions. These are EPC C1G2 RFID tags with batteries used for sensor and data logging. Since the communication is passive, batteries last a lot longer and are generally a better fit for cold chain and CRT logistics.
- Battery-free solutions. These are EPC C1G2 RFID tags with sensors and without batteries. No data logging is possible without batteries so these systems require RFID readers close to the tags at all times. These solutions are only fit for very specific applications.
We’ll go deeper into these wireless solutions for cold chain and CRT logistics and explain how they work, what their advantages and disadvantages are and so on.