The Importance of Selectivity and Specificity in Hydrogen Sensing

In addition to its widespread use in the chemical and oil and gas industry, the desire to achieve climate neutrality has sparked global interest in hydrogen. However, the hazards and risks associated with the highly flammable hydrogen are still getting in the way of its adoption. While there have been significant advancements in gas sensing, the sensitivity of sensing technologies to background gases and compounds is a big pain point for the end users.

In this article, we explain how improving sensor selectivity and specificity can drive up user confidence in hydrogen monitoring.

Selectivity, Specificity, and Cross-Sensitivity in Gas Sensing

In gas sensing, specificity indicates the sensor’s ability to respond to a specific gas in the presence of various gases. Meanwhile, selectivity refers to its ability to differentiate target gas from others in a mixture. In other words, selectivity requires identifying all elements in the mixture, whereas specificity does not. To understand the importance of selectivity and specificity in gas sensing, we must also talk about cross-sensitivity, as all three are closely linked.

Take electrochemical sensors, for example. These devices consist of electrodes and an electrolyte. Cross sensitivity happens when background gases trigger a chemical reaction at the electrode’s surface. This reaction could be the same as the one caused by the target gas.

A sensor prone to interference may feel that it is detecting the target gas, causing it to give an inaccurate output. The susceptibility of ammonia sensors to hydrogen is an excellent case in point.

Are All Hydrogen Sensors Prone to Interefering Gases?

Hydrogen is used in various industrial environments with hundreds of gases, fumes, and contaminants surrounding it. It, therefore, becomes challenging for most commercial sensors to monitor H2 concentration with selectivity and specificity. A majority of them end up responding to some background gases while being unaffected by others. For instance, the semiconductor metal oxide and thermal conductivity sensors are highly sensitive to methane.

However, not all hydrogen detectors are created equal. And there are sensors that function with high selectivity and specificity to hydrogen, such as the H2 IntelliSense Slim Hydrogen Sensor.

Advantages of Choosing a Selective and Specific Sensor

1. No False Alarms

Anything from refining processes to cleaning chemicals can produce gases that might interfere with sensor reading. A false positive reading may trigger unnecessary alarms and shutdown protocols. It can impact the integrity of equipment and valves, damaging them in the process. False alarms also cause anxiety in the minds of personnel and reduce productivity. All this can be avoided with reliable sensing technology that does not respond to other gases than the one being monitored.

The IntelliSense Slim is a hydrogen-specific sensor that measures and monitors with accuracy and precision. Regardless of the surrounding environment, the IntelliSense Slim reacts to hydrogen alone. It swiftly detects even the tiniest of leaks, giving users enough time to evacuate or take remedial action.

2. Reliable Leakage Detection

The use of hydrogen spans various industries - ammonia production, petroleum refining, space applications, and power generation, to name a few. It also won’t be long before the roads are teeming with hydrogen-powered vehicles.

Its tremendous potential aside, hydrogen is a tricky gas to produce, store, and transport. A sensing platform that is selective and specific to hydrogen alone is key to building end-user confidence. Our solid-state electrochemical sensor does not react to any other combustible or reducing gases. It can selectively sense hydrogen at any concentration and catch the smallest of leaks well before they become problematic.

3. Accurate Measurement and Monitoring

IGas analysis methods, like spectroscopy and mass spectrometry, are known for possessing remarkable selectivity. But they are also quite expensive, bulky, high maintenance, and nearly not as portable or deployable as solid-state sensors.

The H2 IntelliSense Slim Analyzer offers the best of both worlds as a miniaturized and selective device for hydrogen analysis and purity measurement. Its design makes it easily deployable at source and hard-to-access places. Meanwhile, a robust exterior ensures high performance in the harshest conditions, including moisture-laden electrolyzer operations.

In an electrolyzer, our H2 analyzer can be placed in both the oxygen and hydrogen chambers to prevent explosions and measure H2 purity in parts per million.

4. Enhances Sensor Life

While interfering gases typically cause a temporary change in sensor response, poisons are compounds that can permanently alter their functionality. If a detector fails temporarily or permanently on exposure to contaminants or poisons, it can have serious safety repercussions. Catalytic bead LED sensors are known for being the most vulnerable to poisons, like silicon-based products and lubricants.

Our IntelliSense Slim sensors are highly selective and specific to begin with, thanks to proprietary solid-state electrochemical technology. They can detect the target without influence from contaminants and are resistant to poisons. They are less likely to wear and tear from the effects of interferents, in turn extending their useful life.

The 21Senses Advantage

Accurate and reliable readings will go a long way in building end-user confidence when dealing with a highly flammable gas like hydrogen. And it’s clear that sensor selectivity and specificity are crucial to making it happen.

Our painstakingly researched and rigorously tested technology and design have allowed us to create a hydrogen sensor that you can trust. Every sensor in our H2 IntelliSense Slim series is selective and specific to hydrogen, no matter how many gases and compounds are present in the area. Reach out to us for more information or to book a demo.