A diverse array of products requires transportation in climate-controlled environments, including medicine, perishable foods, cosmetics, beauty products, and advanced technology.
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Regardless of the distance traveled, exposure to extreme heat or cold, or fluctuations between the two, can lead to various issues, including loss of quality or even total loss of the product.
This risk can be addressed through the use of smart shipping containers and advanced sensor technology. These innovative containers allow delicate items to be transported in a highly stable micro-environment.
The Fundamentals of Smart Shipping Containers
The story has remained consistent since the first time someone transported an item sensitive to ambient conditions over a significant distance. That individual required a transport method that not only shielded the item from the usual rigors of travel but also protected it from external and internal environmental factors.
The earliest iterations of transporting goods in rudimentary shipping containers required constant human attention to manage their internal conditions.
As technology and engineering have advanced, climate-controlled shipping containers have greatly reduced the need for human intervention by automating and continuously managing their micro-environments.
Climate-controlled shipping containers continue to evolve, with modern versions being significantly more advanced than the refrigerated truck trailers commonly used 30 years ago.
IoT-enabled sensor technology now allows these containers to dynamically adjust to temperature, airflow, and humidity changes, ensuring that conditions inside the container remain stable.
Real-time data collection also facilitates remote monitoring and management while the container is being transported, adding an additional layer of safety and security for the cargo within.
Key Design Considerations for Smart, Climate-Controlled Shipping Containers
A number of factors should be considered when developing smart, climate-controlled shipping containers. These include:
- The type of cargo
- The length of travel time
- The modes of transportation being employed
For instance, pharmaceuticals often require precise temperature control within a narrow range, while perishable foods may need both temperature and humidity regulation. Some instances may even demand more complex controlled atmospheres.
To maintain the climate within a shipping container, regardless of the trip duration, it is crucial to go beyond basic temperature regulation. Effective climate control requires a combination of suitable hardware and advanced sensor technology.
Shipping Container Hardware
A shipping container should have a durable exterior, but its design should also include a range of other features.
- Insulation: High-quality insulation materials such as polyurethane foam or fiberglass panels are able to prevent heat transfer and maintain temperature.
- HVAC system: A refrigeration unit or heater/air conditioner should be installed to actively manage internal humidity and temperature.
- Thermostat and control system: An electronic control system should be installed to efficiently monitor and regulate the container’s temperature and humidity levels.
- Power supply: The container should feature an integrated power source (for example, a diesel generator), or it should have the capacity to connect to an external power source.
- Structural framing: A sturdy aluminum or steel frame is necessary to ensure structural integrity and enable efficient stacking and transport.
- Weatherproofing features: Seals, coatings, and gaskets should be used to ensure the container remains airtight, as well as helping to protect against moisture, dust, and pests.
Shipping Container Sensors
The use of advanced sensor technology can be the deciding factor between a smart shipping container that effectively safeguards its contents and one that risks damaging them.
Climate control systems in a smart shipping container should incorporate several key sensors to ensure optimal performance.
Humidity Sensors
These sensors help manage airborne moisture, a key consideration in preventing damage from dryness or condensation, which can negatively impact a wide range of products, including textiles, electronic components, and foodstuffs.
Capacitive humidity sensors are commonly employed in shipping containers because they can accurately measure relative humidity (Rh) across a wide range and are resistant to chemical exposure or temperature fluctuations.
Carbon Dioxide Sensors
Carbon dioxide (CO2) sensors are essential in containers transporting perishable goods, particularly those transporting organic products such as fruits and vegetables that respire during transport. Accurately monitoring CO2 levels helps to manage these perishables' respiration rate and quality.
Nondispersive infrared (NDIR) sensors are a popular choice for CO2 detection. These sensors are able to measure the absorption of infrared light as it passes through sampled air, providing precise quantification of the container’s CO2 levels.
Oxygen Sensors
Like CO2 sensors, oxygen (O2) sensors are essential in controlling oxygen levels—another important consideration in reducing spoilage for organic materials. This is especially the case when transporting fruits and vegetables, which produce oxygen, and in preventing fire hazards in containers transporting flammable products.
Zirconia sensors and electrochemical cells are commonly employed technologies for measuring oxygen levels. These sensors provide rapid, reliable measurements and operate over a wide range of oxygen concentrations.
Temperature Sensors or Probes
Temperature probes or sensors are essential for measuring a shipping container’s internal temperature, particularly when shipping goods such as pharmaceuticals, electronics, and perishable foodstuffs.
Resistance temperature detectors (RTDs), thermocouples, and digital sensors are commonly used temperature sensors. Each of these instruments provides continuous, real-time data that allows for immediate adjustment where required.
Key Considerations for Shipping Container Sensors
One critical factor affecting the contents of all shipping containers during transit is the external environment.
Despite advances in sensor technology, shipping containers remain vulnerable to external conditions. Additionally, the transportation process itself can impact the contents, as a range of factors influence the container’s exterior, which in turn affects its internal environment and components.
These external factors include many of the same variables that must be controlled within the container, such as temperature and humidity.
Source: Amphenol Advanced Sensors
| Factor |
Effect |
| Temperatures |
Extreme temperatures can cause mechanical stresses and potential failure of sensor components and may reduce battery performance and lifespan. |
| Moisture from Humidity, Condensation, or Direct Contact with Water |
Moisture can corrode metal components and short-circuit electrical connections, and high humidity can affect the accuracy of certain sensors. |
| Chemical Exposure (such as Saltwater) |
Corrosive chemicals, such as saltwater, can rapidly degrade both the external and internal components of sensors, leading to corrosion of metallic parts and degradation of electronic circuits. |
| Pests and Other Environmental Factors |
Pests can damage sensors by chewing through cables and housings, while environmental factors like dust and debris can clog mechanisms and impair sensor function. |
Mitigating Degradation via Environmental Conditions
Addressing the environmental challenges faced by shipping container sensors during transit requires solutions akin to those used for managing sensor technology in stationary applications, such as commercial or residential HVAC systems: a proper investment in custom advanced sensor technology.
Transit environments can be highly unpredictable, making it challenging to anticipate every potential scenario. However, like the shipping container itself, integrated sensor technology must be robust enough to withstand extreme and variable conditions.
Custom advanced sensors for shipping containers are specifically engineered to endure the stresses of transit environments, unlike standard off-the-shelf sensors. These sensors are designed to maintain accuracy even in harsh conditions.
Working with an advanced sensor manufacturer allows for customization in several key areas: selecting materials that resist corrosion and wear, implementing protective encasements to shield delicate components from chemical or physical damage, and enhancing software to ensure a strong dynamic response to unexpected environmental changes.
Additionally, advanced sensors can be equipped with self-diagnostic capabilities to alert users to potential issues before they lead to failure, ensuring continuous operation and reliability throughout the sensor’s lifespan.
Investing in advanced sensor technology for smart shipping containers ultimately pays dividends with every journey, providing peace of mind and protecting valuable content.
Summary
Shipping containers must provide a high level of protection for their contents across various fronts and in various environmental conditions.
By integrating advanced sensor technology into smart shipping containers, these will be more equipped to ensure that goods are delivered in the best condition possible, regardless of where they are transported to or how long it takes them to reach their destination.
Acknowledgments
Produced from materials originally authored by Amphenol Sensors.
This information has been sourced, reviewed and adapted from materials provided by Amphenol Advanced Sensors.
For more information on this source, please visit Amphenol Advanced Sensors.