“Gas sensors are invisible sentinels that detect invisible dangers. “We can create a safer industrial environment and ocean through localization and technological advancement.”

At the 10th Advanced Sensor Forum 2025 held on December 4, Lee In, CEO of ELT Sensor, gave a presentation on the topic of ‘Gas sensor technology and application cases applicable to ships and marine environments.’

CEO Lee In emphasized that gas sensors are key devices that prevent various hazards such as explosions, suffocation, poisoning, and leaks, and introduced their potential for use in the ship and marine sectors and the achievements of domestic production.

To understand the basic performance of a gas sensor, two key factors must be understood: measurement range and accuracy.

The range within which a sensor is reliable and how much it deviates from the standard value are directly related to safety.

While there are various technical terms such as response time, reproducibility, and drift, users should at least be familiar with the measurement range and accuracy, Lee explained.

The principles of sensors are broadly divided into two types.

There are two types of methods: a non-contact method that uses light and a contact method that uses chemical reactions.

The representative non-contact method, non-dispersive infrared (NDIR), utilizes the property of specific gas molecules to absorb light of specific wavelengths, resulting in excellent selectivity and a long lifespan of over 10 years.

On the other hand, electrochemical sensors measure current through oxidation-reduction reactions, and although they have a short average lifespan of two years, they can precisely measure even low concentrations.

Semiconductor sensors are widely used due to their low cost, but their accuracy is limited due to the presence of many interfering gases.

There are also various installation forms. They are classified into fixed, portable, modular, and transmitter types, and the selection varies depending on the purpose of use and technology level.

Recently, its use has expanded to include air quality measurement and greenhouse gas monitoring in smart cities and smart factories.

In particular, greenhouse gases emitted from semiconductor factories and ships are treated using equipment called scrubbers, and sensors are essential for measuring emissions before and after treatment.

The importance of gas sensors in the shipping industry is even greater. Ships have many enclosed spaces, so a gas leak can lead to an explosion or suffocation.

Combustible gases (methane, propane, etc.) are used for explosion detection, hazardous gases (CO, NH₃, etc.) are used for poisoning prevention, and combustion gases (SO₂, NO, CO₂, etc.) are used for emission monitoring.

Special vessels such as submarines have difficulty ventilating, so CO₂ sensors must be installed.

The installation area is centered around hazardous areas such as the pump room, engine room, fuel tank, and exhaust gas system.

The representative suggested three ways to utilize sensors on ships: △continuous measurement using fixed sensors, △entry into dangerous areas using portable sensors, and △real-time monitoring using monitoring systems.

Above all, shipboard sensors must be internationally certified, and explosion-proof certification and performance certification are mandatory.

This is not simply a matter of installing the equipment; the accuracy and reliability of the sensor module itself must meet international standards.

Safety in confined space work was also an important topic.

Any space that is not well ventilated is considered a confined space and must be adequately ventilated before entry.

CEO Lee In emphasized that “at least 10 times the volume of outside air must be injected into the enclosed space to be safe,” and that ventilation must be maintained at a rate of 20 times per hour even during work if polluted gases are generated.

The lifespan of gas sensors is also crucial. The lifespan varies significantly depending on the method, with electrochemical sensors lasting two years and optical sensors lasting ten years. Just because a sensor is installed doesn't mean you can be sure of safety, and if regular inspection and replacement aren't done, the sensor may malfunction and fail to prevent an accident.

Domestic companies' efforts to localize products are also noteworthy.

CEO Lee In said, “ELT Sensor is reducing its dependence on overseas companies by securing the capacity to produce everything from basic materials to modules and measuring devices in-house. This is a significant technological advancement that can contribute not only to the safety of ships and industrial sites, but also to reducing greenhouse gases and protecting the environment.”