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You really want to measure that H2S range??

29-Apr-2024Emissions monitoring | Fenceline | H2S | H2S monitoring | Industrial | Oil & Gas

You really want to measure that H2S range??

Requests to measure hydrogen sulphide (H2S) in ambient air at unthinkably high levels seem to be at odds with our efforts to detect and report single-figure parts per billion H2S emissions. So, why are we asked for such high ranges?

We think this may be explained by operators who are used to measuring high concentration in a gas stream – typically biogas or industrial – and then simply transferring the range across when looking at fenceline monitoring. It’s great to see the growing interest in monitoring fugitive emissions at site boundaries – including H2S – but we need to dial back the gas range expected when looking at ambient pollution.

H2S sensors for gas stream measurement are offered at parts per million ranges from 0-50ppm to 0-10,000ppm. Bear in mind that US Department of Labor guidelines say that H2S odour becomes offensive at only 3-5ppm, with prolonged exposure causing headaches, nausea and insomnia, and causes “nearly instant death” at 1,000-2,000pm. Dilution of any emission in swirling ambient air means that parts per million measurements are inappropriate, and even significant H2S leaks usually register peaks of just a few parts per billion by the time gas has reached the fence line.

That’s why the AQMesh sensor measures from 0-10,000ppb (0-10ppm), with a limit of detection of less than 1ppb. Measuring at such low levels means operators can pick up emissions much earlier and much further away from the source than would be the case with the higher range sensor typically used for measuring the gas stream. Picking up a low level at a suitable point on the industrial boundary should avoid dangerous levels of H2S building up near the source.

Monitoring in ambient air is gentler on sensors, too, so if you are used to sensor poisoning and condensate problems, that benefit does offset the ‘needle in a haystack’ challenge of picking up fugitive H2S emissions. With the potential to move an AQMesh pod from location to location, and add a wind speed and direction sensor to help with source apportionment, it is very satisfying to support our users doing just that.

Who’s behind AQMesh?

18-Apr-2024Company news | Emissions monitoring | Gas detection | Methane

Who’s behind AQMesh?

Did you know that we have always been part of wider group of companies, offering a portfolio of emissions, leak detection and gas stream monitoring products, software and services, specialising in methane?

For decades, the Ecotec group has been designing, selling and supporting equipment for monitoring landfill gas and biogas. Gazomat in France developed laser-based portable and mobile equipment, used extensively to check very low level methane emissions from natural gas pipelines and networks. California-based Oxigraf specialises in oxygen sensor technology.

What does this mean for AQMesh? Our range of ambient air monitoring sensors – including TVOC, H2S and CO2 – matches and complements the group portfolio of industrial emissions monitoring solutions. We now also offer a methane option, delivering readings alongside all the other channels AQMesh provides, including wind speed and direction. This means we have continuous, stationary methane monitoring options at sub-ppm limit of detection with the laser sensor, or a lower sensitivity small sensor CH4 option.

Let us know if you’d like to know more about our industrial fenceline monitoring options or an introduction to the rest of the Ecotec range of equipment.