Bakhram Gaynullin develops smarter gas sensors to measure methane

Methane is one of the most powerful greenhouse gases and has a significantly greater effect on global warming than carbon dioxide in the short term. While CO₂ is routinely measured with well-established technology, methane remains harder to track reliably. One reason is that methane’s infrared absorption spectrum overlaps with water vapour, which is present almost everywhere in our natural environments.

In his doctoral research, Bakhram Gaynullin refines and expands the capabilities of NDIR (nondispersive infrared) gas sensing technology. This technique, already used industrial and environmental applications, is considered to be cost-effective and requiring minimal maintenance. However, it has a major limitation - it has difficulties to distinguish between gases that absorb light at the same infrared wavelengths.

A way to detect methane

"Sensors that rely on the standard NDIR technique estimate gas concentrations based on absorption within specific optical bands. As a result, they cannot selectively quantify the target gas when its absorption spectrum overlaps with that of other gases. Methane and water vapor are a perfect example of this," says Bakhram Gaynullin.

To overcome this challenge, he developed a novel multichannel sensor system. One channel measures the combined absorption of methane and water vapour, while a second channel is specifically designed to isolate the water vapour signal. Additionally, a third channel serves as a reference—known as the zero channel—tuned to a wavelength where none of the target gases absorb. By comparing the signals from these three channels, the system can accurately calculate the true methane concentration, even in humid environments

“It’s like subtracting the water signal from the total measurement that gives us the true methane reading,” he explains.

As part of his PhD, carried out at the company Senseair, Bakhram Gaynullin designed and constructed a complete test and calibration system. He then took the system into the field for real-world trials, including cow farms in Latvia and coastal environments. Each test cycle brought new insights and improvements.

“There’s a lot of technical development behind this. It’s a constant process of designing, testing, evaluating, and then doing it all over again,” he says.

Applications in climate monitoring and industry

The implications of his work extend far beyond academic interest. From arctic wetlands to biogas facilities, there is growing urgency to monitor methane leaks more effectively—not only for climate protection, but also for safety and regulatory compliance. Bakhram Gaynullin’s research could help make reliable methane sensing more accessible and scalable.

“Currently, there is a lack of cost-effective instruments for reliable methane sensing under environmental conditions. Such tools are essential for accurate monitoring of atmospheric methane concentrations and for effective leak detection across various applications.” he notes.

His sensor designs also consider manufacturability from the start, a benefit of working closely with industry during his PhD. 

“You think about whether a new solution can be produced and implemented right away. It’s a good combination of science and practical development,” he says.

Bakhram Gaynullin began his career as an engineer and laser physics researcher in one of the republics of the former Soviet Union, now the independent state of Uzbekistan. After relocating to Sweden, he worked in the solar energy sector before joining Senseair, a company specializing in gas sensing technologies, as an industrial PhD student.

Welcome to Bakhram Gaynullins defense of his doctoral thesis:

Implementation of NDIR Technology for Selective Sensing of Gases with Common Absorption Spectra
Defense date: June 10, 2025, at 10:00 AM
Location: Room O102, Mid Sweden University (Sundsvall campus) and via Zoom. 

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