How Gas Detectors Work

Gas detectors are a crucial first line of defense against the dangers of undetected gas leakage on board a ship. Finding out how gas detectors work will help you choose the right solution for your container.

Reliable, robust gas detection methods are crucial to effectively protect lives at sea – dangerous gases are a common hazard on board, and storage and transportation at sea present their unique challenges. Understanding how your gas sensor works can help simplify the decision-making process when choosing the equipment and technologies that keep your teams safe. 

The Science Of Gas Detection

Gases are a specialized risk that is increased by their presence. In most cases, only a minimal concentration of gas is needed to cause significant harm to health or the possibility of combustion or explosion, especially within the confined spaces found onboard most sea-going vessels. Most gases are invisible – there are many other gases that are colourless and odorless. These characteristics mean gas poses a unique risk that is impossible to mitigate without the use of specialist technology – but it’s only in recent years that we’ve had access to more sophisticated automatic detection methods which can be calibrated at the touch of a button and provide 360, 24/7 protection against gas leaks. 

Gas detection technology has come a long way since its development in the late 1800s. Before automatic electronic methods, people working with potentially hazardous gases relied on various primitive methods to protect themselves against gas’s physical and environmental dangers, including the canaries used by miners to indicate a potentially toxic build-up of gases underground. 

Modern gas detection methods have evolved significantly since then, of course, using a combination of technologies and accurately and efficiently identifying hazardous gas levels and saving lives.

How Do Gas Detectors Work?

To answer this question efficiently, you must first know what type of gas detector you are dealing with. Different gas sensors have other operating systems, which vary according to the type of gas they are designed to detect. Gas detectors typically fall into three broad categories, all of which operate slightly differently:

Electrochemical: Highly sensitive electrochemical gas detectors measure poisonous gases like carbon monoxide. They detect electrodes in the air and send an electric current to set off the alarm. 

Catalytic Bead: Using a platinum-treated wire coil, this type of gas detector most commonly identifies combustible gas in the air as the coil oxidises upon contact with the gas, tripping an alarm. Catalytic gas detectors are unbelievably common, particularly for use in domestic contexts. 

Infrared: Advanced infrared technology uses emitters and receivers to precisely measure gas levels in the air. Most commonly used for hydrocarbon and combustible gases, Infrared gas detectors use the light transmission to determine what type of gas is present and at what level, sounding the alarm when high concentrations are present. 

All gas detectors share a common feature. Once the gas has been detected at critical levels, they activate the alarm by means of a loud audible alarm, sometimes accompanied by visual signals, such as flashing lights.

Which Type Of Gas Detector Is Most Accurate? 

While all gas detectors offer precision, some have improved the safety benefits over most. In fact, they simultaneously reduce the risk of human error and malfunction, ensuring that the gas detector operates at its full capacity and provides complete safety. 

The type of technology used within a gas detector depends on several factors – including where it will be used, what you require it for, and the variety of gases it is designed to detect, as different gases need different detection techniques.

Electrochemical sensors are mainly used for non-flammable gases, in particular O2, H2S and CO. Our Model 4 uses a catalytic sensor – and although it doesn’t work in an inert atmosphere and requires calibration, it can collect hydrogen, unlike an infrared sensor. 

When choosing a fixed gas detector, you have a choice, but infrared is much more expensive due to being more stable and offering a host of additional benefits.

The additional advantage of LEL Infrared technology is that it offers a significant advantage over other gas detection methods. It is shielded from two threats to the gas detector function: the poisoning and drift of the sensors. With no need to worry about these two issues (or constantly check, service and calibration to avoid them) and an extended battery life, you can rest assured your gas detector is ready for action at all times.