Monica Heck, for IEC

28 February 2026

Smart sensors with on-board processing and communication capabilities are now monitoring the plant from satellites and other observation ecosystems to track drought, monitor crop data and estimate agricultural yield. Source: IEC

The thermometer and the barometer were born in the 1600s and, since then, sensors used for environmental purposes have continued to become smaller, smarter and more powerful. Within the next decade, quantum sensors will be leveraging quantum mechanics like superposition, atomic states and entanglement to detect minute changes in the environment.

In the meantime, smart sensors with on-board processing and communication capabilities are now widely used across the internet of things (IoT). Software-based virtual sensors generate results without the need for physical hardware, offering cost benefits, reduced signal noise, greater flexibility and an alternative in situations where extreme conditions do not permit the placement of a physical sensor.

Today, it is even possible to monitor the planet from space, using artificial intelligence (AI) to combine data from satellites and other observation ecosystems to track drought, monitor crop growth and estimate agricultural yield. A very recent AI model now functions like a virtual satellite, harnessing the power of AI to combine petabytes of data from public sources — like optical satellite images, radar, 3D laser mapping and climate simulations — into an analysis of the world's land and coastal waters, allowing it to track changes precisely over time without relying on the positioning of specific satellites.

Printed electronics, AI and distributed networks

In parallel, the emergence of printed sensor technologies to monitor air, water, soil and climate has been made possible thanks to the development of new materials such as graphene, conductive polymers and biodegradable substrates. An IEC technical committee, IEC TC 119, prepares standards in that area, notably the IEC 62899 series, which define substrates used in the printing process to form electronic components.

Just recently, researchers from the Lausanne-based engineering university EPFL developed the first compostable and sustainable smart sensing tag that signals when shipments of medicines or food have exceeded a safe threshold temperature. An increase in computational abilities, supported by AI and machine learning, is driving sensor development, according to Ulrike Lehmann, CTO at a Swiss company focusing on water and soil analysis, that manufactures small format, solid-state pH sensors.

“For over 100 years, glass electrodes have been the gold standard when it comes to the precise measurement of pH,” Lehmann said. “However, to measure pH in very small volumes in food or in a medium like soil where glass is too fragile or impractical, our completely solid-state 1 mm x 3 mm sensors can help.”

The combination of multiple, smaller sensors of different natures in a distributed network format and an increased need for on-site measurement is driving interest from industries like smart farming for the in-field measurement or nitrates and other components, according to Lehmann. “They are seeking low power consumption, reliability and small form factors.” (For more on the potential for ultra-low power, read this e-tech article).

IEC work for a wide variety of sensors

Hojun Ryu, Secretary of IEC TC 47/SC 47E, the subcommittee that prepares standards for discrete semiconductor devices, including sensors, describes sensors for environmental monitoring as combining a transduction element that converts a physical or chemical phenomenon into a signal with signal conditioning and a data interface. “Our pressing focus is to standardize the semiconductor sensor device or module building blocks,” he said. “We are particularly focused on consistent test methods for key sensor device types, as well as clear control or interface schemes and low-power specification practices for smart sensors, which are important for remote outdoor nodes.”

TC 47/SC 47E focuses on the fundamental discrete semiconductor components at the heart of modern environmental monitoring systems: photosensitive devices, temperature sensors and gas-sensitive discrete structures. Iterations include microelectromechanical devices (MEMS), physical sensors for pressure, temperature, humidity, flow, acoustic or vibrations that support meteorology and corrections for gas or particulate matter measurements. Ryu said this technology is mature, low cost and reliable, but long-term stability is dependent on enclosure, contamination control and calibration strategy.

Detecting pollutants in the air and the water

Electrochemical sensors that detect pollutants and chemical changes in the air, water and soil by converting chemical reactions into measurable electrical signals are compact and provide good sensitivity at low power, but suffer from cross-sensitivities such as temperature, humidity and interferents such as aging or drift and come with a calibration and maintenance burden, according to Ryu. Drift refers to the gradual deviation of a sensor's output from its true value over time, even when the input remains constant.

Semiconductor chemiresistors or metal-oxide (MOx) gas sensors detect gases by measuring changes in their electrical resistance caused by chemical interactions with the surrounding air. These are often used in low-cost nodes, dense networks or IoT deployments, explained Ryu, but their selectivity is challenging. They also suffer from drift and need frequent recalibration.

Optical spectroscopy for gases, especially laser-based, uses light to analyze gas properties by measuring how gas molecules absorb or emit light at specific wavelengths, revealing their identity, concentration, temperature and structure. Ryu noted that this offers high specificity and long-term stability, making them strong for CO?/CH? and greenhouse-gas monitoring. However, they cost more, are bigger and consume more power than simple electrochemical or MOx sensors.

Optical particulate matter (PM) sensors measure airborne dust or pollution via light scattering photometry. They are compact, affordable and good for high-time-resolution indicative monitoring and hotspot detection. However, Ryu said that they are sensitive to particle size distribution, composition and humidity, and need careful correction or validation against reference methods.

Finally, water-quality sensing modalities include the various technologies used to detect, measure and monitor the physical, chemical and biological characteristics of water such as conductivity, turbidity or optical backscatter and fluorescence. According to Ryu, these sensors can measure physical, chemical or biological proxies that go beyond data points to provide wider situational awareness. High turbidity might speak of recent storms, illegal constructions or high concentrations of certain chemicals. A drop in oxygen might alert to population die-offs or microbial blooms to come. These sensors do, however, fall victim to fouling, corrosion and drift, and cleaning and calibration dominate their life-cycle cost.

Standards are key

“Standards make sensor performance claims comparable and enable trusted data quality by defining parameters like sensitivity, linearity, hysteresis, stability and reliability tests. They support interoperability and scalable deployment, especially for “smart sensors with digital control and low-power operation,” Ryu said, who explained that the generic standard series IEC 60747 covers global specifications for sensors, semiconductor sensors, smart sensors, photodiodes and phototransistors.

Developed by IEC TC 72, the recently published IEC 60730-2-23 also helps manufacturers ensure that sensors perform safely, reliably and accurately under normal and abnormal conditions and that any embedded electronics deliver a dependable output signal. (For more on TC 72 Standards, read this e-tech article). ISO/IEC 29182-1 published by the joint subcommittee established between the IEC and ISO to develop standards for the IoT, facilitate the design and development of sensor networks and improve their interoperability, making them plug-and-play, so that it becomes fairly easy to add/remove sensor nodes to/from an existing sensor network.

Manufacturers can also use the IECQ (the IEC Quality Assessment System) approved component scheme (product certification), which covers electrotechnical component products, assemblies and related materials.

The impact of sensors on the environment

While sensors are used to give information on the environment, polluting substances and the emission of CO? for instance, one must not forget that they can have an impact on the environment as well.

The same joint IEC/ISO subcommittee deals with the requirements of underwater acoustic sensor networks (UWASNs). The environmental impact of these sensors is not negligible and should be taken into consideration to minimize the impact on wildlife, said Dr Kathy Matara, Convenor of the working group that brings together a combination of network, bio acoustics and marine biology experts to compile research on the effects of sound on marine life.

“Soundwaves that carry data travel well underwater of course, but in a silent habitat, the wisest network should be all or largely silent,” said Matara, who lives by the ocean in Hawaii. “We know RF won’t travel underwater, and laser is largely untested. Cable would be ideal.”

The working group has kicked off a proposed new work item, leading to the publication of a standard in due course, which aims to look at the environmental and ecological effects, risks and considerations of underwater acoustic signaling.

An ocean-wide deployment of loud acoustic sensors chattering to each other 24/7 leaves nowhere for marine life to flee, Matara said. “Cetaceans depend on echolocation to navigate and find food, corals depend on the soundscape of the surrounding reef ecosystem to thrive. We need to take a closer look at the safety of underwater sensors for marine life. To create significant damage or risk extinction in the ocean would be dangerous, not only for the ocean, but for humanity.”

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