As a technology, IoT promises to improve human safety by automating operations in harsh conditions unsafe for workers. Consider the example of a military drone deployed in a rugged, remote combat terrain to gather mission-critical surveillance data. Despite extreme weather conditions, the drone collects the data, processes it and communicates it to the base station. The drone is a classic specimen involving sensors, electromechanical components, semiconductors and so on, which must sustain harsh environments without compromising performance.
Extreme temperatures, high humidity, exposure to shocks, vibration, contaminants and strong electromagnetic fields degrade components quickly, causing those to fail or operate less effectively. This is a challenge when designing mission-critical IoT systems. System design has to source parts that comply with standards for harsh environments and include tests to validate that the technology installation works effectively for its intended operational lifespan.
Adverse Impact on IoT Systems
Consider the case of deep well drilling in mining or oil and gas industries. The technology has to withstand progressively high temperatures due to the geothermal gradient of deep wells. In such applications, IoT components must function effectively at temperatures above 200°C. Otherwise, system failures result in costly rig downtime. In such cases, active or passive cooling to maintain the operational temperature range is impractical. What’s needed are components able to operate at peak capacity in temperatures over 200°C.
High vibration levels can cause system failures. During product design, in addition to modeling and analysis to determine potential vibration levels, you must plan to test for system reliability in harsh conditions. Some industrial sectors require advanced tests like Highly Accelerated Life Tests (HALT) and Highly Accelerated Stress Tests (HASS). These tests validate the system’s operational and destructive limits against potential vibration issues that might occur during the system’s life span.
Hostile environmental variables like heat, humidity, mechanical stress, electromagnetic radiation and even physical assaults quickly degrade the overall performance of IoT systems. For example, radio interference from co-located Wi-Fi and Bluetooth networks can potentially increase latency, energy usage and packet loss in a low-power, low-range IoT application. Temperature variations can affect electrical and electronic components, causing clock drift, battery discharge and degradation in low-power radios. Using components designed to meet harsh environmental standards can sustain IoT. TTI has a catalog of products that meet harsh environmental requirements.
Industry Standards for Extreme Conditions
Adhering to industry standards to sustain harsh environments is essential during system design. The International Electrotechnical Commission (IEC) defines the IP (Ingress Protection) code under the IEC 60529 standard. The IP code designates the various types and degrees of protection afforded to electrical components, along with testing and confirmation procedures.
The National Electrical Manufacturers Association (NEMA) defines a common standard for protective enclosures in harsh environments. NEMA 250 covers more harsh conditions than the IP code. It provides ratings for hazardous and nonhazardous indoor and outdoor factors such as water, foreign materials like fiber, dust and corrosive substances and gases.
IoT Design Considerations for Harsh Environments
IoT systems use resource-constrained electronic components to minimize energy consumption and device footprint. Industrial IoT design must ensure that the sensors used in indoor and outdoor environments can withstand harsh conditions while remaining connected and generating data. In oil refineries, for example, the sensors must accurately and continuously monitor extreme conditions while exposed to extreme temperatures, pressure, explosive environments, shock, dirt and moisture. In factories, hard hats that keep workers safe should use sensors that perform reliably in environments with high UV radiation and dependably alert the wearer when UV exposure exceeds a threshold. Ensure you use sensors that are adequately tested and vetted for harsh environments.
Reducing losses and thermal stress is essential when designing IoT systems for extreme conditions. In industrial platforms, you must prevent data transmission losses between PLCs, sensors, actuators and motors. Suitable connectors must be used to seal off and protect against environmental challenges like shock, vibration, dust, water or EMI.
IoT systems can be subject to excess current and overvoltage flows in certain industrial applications. Systems can also be exposed to excess electrostatic discharge (ESD) and electromagnetic interference (EMI), impacting their performance and longevity.
Integrating protection technologies during design is essential to improve system robustness. Voltage supervisor ICs can provide overvoltage/under-voltage protection (OVP/UVP). You can use solutions like current limiters and fuses for overcurrent protection. Similarly, integrating EMI/ESD protection technologies ensures the long-term dependability of the design.
Conclusion
Most industrial IoT applications involve exposing systems to extreme conditions. When exposure is unavoidable, the optimal choice is to design systems with rugged components built for harsh environments and thoroughly tested for compliance with IEC 60529 and NEMA 250 standards. TTI has partnered with many suppliers to offer sensors, resistors, capacitors, connectors, and other electromechanical components to meet your design needs.
Sravani Bhattacharjee has worked as a tech leader at Cisco, Honeywell and other companies where she delivered many successful innovations to the market. As the principal of Irecamedia, she collaborates with Industrial IoT innovators to create compelling vision, strategy and content that drives awareness and business decisions.
