Securing Your Cold Chain
With Smart Passive Loggers
Introduction
A key component of any cold chain operation is temperature monitoring. Storage facilities are usually well monitored with solid processes and procedures in place, and trucks and containers are also monitored (although usually less so than warehouses). Unfortunately, it’s usually difficult, and sometimes impossible, to tie all of these together to create a “cold chain of custody”. As well, transient locations such as loading docks and airport tarmacs are unmonitored and often the weakest link in the cold chain.
For all these reasons, package-based temperature loggers are a critical part of cold chain logistics. Whether you’re a logistics provider looking to provide your customers with verifiable trip temperature profiles, or a logistics customer with a “trust with verification” approach, portable temperature loggers included with your shipments are a must-have part of your cold chain.
Traditional temperature loggers generally fall into three broad categories: chemical strips, USB loggers, and cellular loggers. Recently, though, smart passive data loggers have entered the market, and are becoming more popular for a variety of applications.
Today, we’ll take a closer look at smart passive loggers, their pros and cons, and possible applications.
Traditional Monitoring Options
Broadly speaking, traditional temperature logging solutions fall into three categories: chemical strips, USB loggers, and cellular loggers. Each has its advantages and disadvantages.
Temp Strips
Chemical strips aren’t considered loggers in the normal sense, but we’re including them here because they offer an attractive alternative to data loggers in some cases. Usually, they indicate a temperature excursion by a darkening of one of the indicating circles, and longer excursions are shown in larger circles.
The appeal of these single-use indicators is their simplicity and low cost. This makes them well-suited to “last leg” distribution, such as to pharmacies, medical offices, and even consumers. For instance, including a strip with a shipment of corneas to an opthamology practice provides the receiver with some assurance that the shipment was kept at a safe temperature throughout the journey.
Unfortunately, temp strips carry with them significant disadvantages as well. As they aren’t actual data loggers, there’s no data collected at all, no history kept, and no chain of custody for the shipment. In the example above, if the person receiving the shipment doesn’t read the indicator properly, a temperature excursion won’t be caught. In addition, there’s no record of the temperature history saved for future reference in case problems arise.
For these reasons, the use of these chemical strips is fairly limited in critical cold chain applications, and even in the applications where they are used extensively, they’re far from an ideal solution.
Temp Strips
USB data loggers have been the standard for critical cold chain applications for decades. They’re relatively inexpensive, although the cost can vary dramatically depending on features. At the same time, their large storage capability and the ubiquitousness of the USB interface made them a good fit for large scale shipments in highly regulated applications such as pharma.
Nevertheless, USB loggers have their own set of issues. The USB interface means that a PC is required to read the data, which usually means that the shipment must be put into quarantine while that is processed. The USB interface itself is problematic in large security-conscious organizations, where USB ports are increasingly regarded as security risks.
Finally, USB loggers have historically come with somewhat limited software support. While a PDF file is usually available from the device just by plugging it into a PC, extracting any real data requires downloading a program from the company website. In addition, cloud support is something of an afterthought, typically requiring a subscription.
Cellular Loggers
With the advent of inexpensive and semi-ubiquitous coverage, cellular loggers have been more common, particularly for large pallet-based shipments. These have the significant advantage of providing real-time updates, so that cold chain managers can be alerted immediately if there is an excursion.
The major disadvantage of cellular loggers is their cost. While cellular hardware and service costs have come down in recent year, cellular loggers are still many times more expensive than their USB counterparts.
Of course, there are still many areas where cellular coverage isn’t available, and there are many situations where exception alerts aren’t actionable, for instance if the driver can’t be reached.
Smart Passive - An Alternative
The development of new low-power wireless technologies, combined with the emergence of cloud computing and the ubiquity of mobile phones has created a new class of data logger that combines these technological developments to create solutions that are superior to USB-based data loggers, at a similar cost. In addition, they can be used in workflows that previously had no viable solution.
What are “smart passive” data loggers? First, they’re wireless, using low-power wireless technology to communicate with a mobile phone. This eliminates many of the issues associated with a USB interface, and also provides a clean, simple user experience that is familiar to any mobile phone user.
Second, smart passive data loggers are cloud connected by design. While USB data loggers have a cloud subscription service available for storage, it tends to be an afterthought, and a somewhat cumbersome interface. Because smart passive data loggers use a mobile phone to communicate with the cloud, there’s no need for separate uploading, organizing, or emailing.
Finally, smart passive data loggers are cost-effective. Because there is no recurring cost and very low hardware cost associated with low-power wireless, the devices are competitive with USB data loggers, and far below cellular loggers.
Of course, cellular loggers still have the advantage of providing real-time exception notification, but as we’ve discussed, these are only valuable if the alerts can be acted upon.
Wireless Options
Since smart passive data loggers work in conjunction with a mobile phone, their options for wireless connectivity are limited to those available to a standard mobile phone: Wi-Fi, Bluetooth, and NFC.
Wi-Fi has the advantage that it is very high bandwidth, and has excellent range. It’s seldom used for data loggers, though, owing to its high power consumption, as well as a complex setup process that doesn’t lend itself to use in “transient” devices such as portable data loggers.
Bluetooth has been around for a while, and the technology keeps improving, both in terms of range and power consumption. The big advantage of Bluetooth is its range. With a mobile phone or a dedicated gateway, even in a large receiving area all of the tags will be accessible. Bluetooth can be a bit slow to connect initially, though. Also, there’s no way to use Bluetooth from a web page, so a mobile app is a requirement.
The most recent wireless technology to be incorporated into mobile phones is Near-Field Communications, or NFC. This is the technology behind mobile payments, and requires the phone to be touching the tag in order to read it (hence the name). It’s been part of every Android phone for the last 10 years, and every iPhone since 2016. The unique feature of NFC is that most phones (all iPhones since 2018 as well as all Android phones) allow background NFC reading, which means the app doesn’t need to be active or even installed to use the tag.
Smart Passive Advantages
The advantages of smart passive loggers over traditional USB loggers extend far beyond connection convenience. Connecting through a mobile phone allows for several enhancements, and, in some cases, brand new features that weren’t previously possible.
Simple Setup
Because smart passive tags connect through a mobile phone, there’s no need for a specialized PC program, or even a PC. In fact, some tags that use NFC don’t even require a mobile app to be installed; they can be controlled using a web address from the tag.
This is a considerable improvement over USB style data loggers, which require a PC with specialized software installed before the logger can be read effectively. They are also much simpler to use than cellular loggers, which generally require some type of provisioning or commissioning process before they can be used.
Scalability
While smart passive tags are simple to use “out of the box”, they can also scale easily to accommodate large and complex business processes. This is because they are primarily cloud-centered, with the majority of the functions and feature based in the cloud rather than the tag or the mobile app.
As an example, the Seguro platform’s cloud-based APIs allow secure, straightforward integration with backend ERP systems as well as Transportation Management Systems, allowing temperature history of shipments to be integrated with other logistics and customer-facing information elements.
Mobile Enabled Features
Because smart passive tags establish connectivity to the cloud through a mobile phone, they (or the platforms that support them) can take advantage of the many features available in modern smartphones.
For instance, it’s often useful to have a visual record of the shipment either before or after shipping. Because smartphones all include a camera, this can be handled seamlessly in a mobile app, or even in some modern browsers.
Similarly, mobile phone cameras can be used very effectively as barcode scanners, allowing information such as pallet ID, serial numbers, and other identifiers to be associated with a shipment.
Finally, while integrating GPS capability into a physical tag would be prohibitively expensive, both in terms of component cost and power consumption, it’s possible to use the location of the mobile phone to add location information for the start and finish of the shipment. This adds yet another useful information element that can be used for looking up recordings or correlating shipments with shipping lanes.
New Workflows
Perhaps the most compelling advantage to smart passive tags is the potential for new features and workflows that aren’t even possible with USB loggers.
Waypoints
Sensified.io’s Seguro loggers include a “waypoint” feature, which allows anyone with a mobile phone to add mid-trip activities, with their locations, to the temperature history. This is ideal for transloading, where a shipment may be transferred from one transportation mode to another. The arrival and departure for a specific dock or location can be logged, and any excursion that occurs can be isolated to the dock, or the first or last transportation mode.
Waypoints are also useful for multi-stop distribution models, where each stop is important to track in the history, but the temperature history is tied to the full delivery route.
Outbound Flow
As we noted previously, temp strips are primarily used in cases where the recipient of the shipment does not have the time, ability, or inclination to perform the steps required to extract a temperature history from a USB data logger. Of course, temp strips have many disadvantages relative to actual loggers, but until the advent of smart passive loggers, there haven’t been any effective alternatives.
With smart passive loggers that support reading without an app (such as sensified.io’s Seguro loggers) there is an alternative that provides full temperature history as well as automatic storage and notification. By setting up the recording at the beginning, including name, thresholds, photos, etc., the sender can set the logger for “instant finish”, and as soon as the recipient taps the device with their phone, the recording is finished, the sender is notified, and the detailed recording information is available to both the sender and receiver.
The advantages of this flow over temp strips are compelling. The receiver has a accurate, detailed, permanent record of the temperature profile, rather than an approximate “dot or no dot” excursion indication. This improves customer confidence, trust, and satisfaction. The sender receives the same data, including a notification that the recording is complete, allowing them to act in real time when there are excursions, and also retain a permanent record in case any issues or concerns arise in the future.
Conclusion
As with most technology, there is no “one size fits all” and it’s important to understand your workflows and your stakeholders when choosing a monitoring solution. For instance, if you’re confident that you’ll get the monitors back, and you have a response team that can ensure that real-time updates are actually actionable, it may be worthwhile to invest in cellular loggers. On the other hand, if traceability and record keeping are not critical, and the cost / risk of temperature excursions is not significant, inexpensive temp strips may be a viable option.
Smart passive loggers, however, are the best option for many organizations. They are superior to USB loggers in terms of features, usability, security, and scalability, and have a far lower price point than cellular loggers. Most importantly, they enable unique workflows, such as sender-centric outbound shipments, that aren’t even possible with other technologies. Because of this, we believe that organizations that adopt smart passive loggers will enjoy a strategic advantage over those using more traditional technologies.
