gas

37 Articles

Street with polluted smoggy air

Serious Chemical Threat Sniffer On A Budget

September 16, 2025 by 40 Comments

Chemical warfare detection was never supposed to be a hobbyist project. Yet here we are: Air Quality Guardian by [debdoot], the self-proclaimed world’s first open source chemical threat detection system, claims to pack lab-grade sensing into an ESP32-based build for less than $100. Compare that with $10,000+ black-box hardware and you see why this is worth trying at home, even if this project might not have the nut cracked just yet.

Unlike your air monitor from IKEA, the device aims to analyze raw gas sensor resistance – ohm-level data most devices throw away – combined with temporal spikes, humidity correlations, and a database of 35+ signatures. Of course, there is a lot of work to be done here on the calibration side, and we don’t have any chemical warfare agents on hand to test against, so we have no idea how well it works, and we’d expect false positives. Still, the idea of taking a more granular look at the data coming off the sensor may bear some fruit.

(Editor’s note: edited with a hefty dash of skeptical salt.)

Featured Image by Arjun Lama on Unsplash

Low-Resolution Fluid Simulation On An ESP32

February 28, 2025 by 2 Comments

Fluid simulations are a key tool in fields from aerospace to motorsports and even civil engineering. They can be three-dimensional and complicated and often run on supercomputer clusters bigger than your house. However, you can also do simple two-dimensional fluid simulations on very simple hardware, as [mircemk] demonstrates.

This build is almost like a simple toy that displays particles rolling around and tumbling as you turn it one way or the other. Behind the scenes, an ESP32 is running the show, simulating a group of particles responding to gravity in a fluid-like manner. The microcontroller is  hooked up with an 3-axis gyroscope and accelerometer, which it uses to track motion and influence the motion of the particles in turn. The results of the simple fluid simulation are displayed on a screen made up of a 16 x 16 matrix of WS2812B addressable RGB LEDs, which add enough color to make the build suitably mesmerizing.

There’s something compelling about turning the display and watching the particles tumble and flow, particularly when they’re all set to different colors. [mircemk] also gave the build the ability to operate in several different modes, running “sand,” “liquid” and “gas” simulations and with dynamic coloring to boot.

We’ve seen some great videos from [mircemk] before, too, like this sensitive metal detector rig. Continue reading “Low-Resolution Fluid Simulation On An ESP32” →

Unconventional Oil Production, All You Need To Know

December 5, 2024 by 48 Comments

It’s fair to say that climate change is perhaps the greatest challenge facing our planet, and while much attention is directed towards solutions to the problems it presents, perhaps there’s less attention given to the the other side of the equation in the hydrocarbon industry. For example we all think we know something about hydraulic fracking wells, but how much do we really know?

[John Thurmond] is a geologist who has recently completed a long career in the oil industry, and he gave an informative talk on the matter at the summer’s EMF Camp in the UK. It makes for an interesting watch, as he leads the viewer through the process in detail, before discussing what should and shouldn’t cause worry.

We learn that fracking has two parts: first the hydraulic fracking itself, and then the re-injection of the toxic fracking well water released from underground along with the oil or gas. It seems the water released from the rocks a 10,000 ft depth contains all manner of toxic and even radioactive compounds, and the usual means of disposal is to inject it back into the ground at a much lower depth. He makes the point that while the hazards associated with the fracking are low, those of the re-injection are high.

The talk finishes up with perhaps the most interesting point, by looking at the nature of opposition to fracking, or indeed any other controversial development. Such things are inevitably surrounded by a swirling mess of half-truths, and his point is that identifying those easily deflected as not true is key to understanding the whole thing. It’s presented from an expert and factual perspective that’s so often lacking in this arena, and thus we think it’s worth a watch.

Continue reading “Unconventional Oil Production, All You Need To Know” →

Scratch And Sniff Stickers And The Gas Panic Of ’87

December 3, 2024 by 41 Comments

Ever wonder how those scratch and sniff stickers manage to pack a punch of aroma into what looks like ordinary paper? The technology behind it is deceptively clever, and has been used everywhere from children’s books to compact discs.

Most Scratch and Sniff stickers are simple nose-based novelties, though they’ve seen other uses as diagnostic tools, too. As Baltimore Gas and Electric discovered in 1987, though, these stickers can also cause a whole lot of hullabaloo. Let’s explore how this nifty technology works, and how it can go—somewhat amusingly—wrong.

The Science