I must admit that I love today’s incredibly small sensors, especially ones I can use in conjunction with my iPhone. When the COVID19 pandemic was in full swing at the beginning of 2021, for example, I picked up a nifty little contactless thermometer, which I now carry around with me in my backpack (see Super-Duper Smartphone Thermometer).

A couple of days ago, my chums at Infineon were kind enough to send me a CO₂GO device, which was created by one of their partners. This bodacious beauty is a mobile CO₂ (Carbon Dioxide) sensor that you can carry in your pocket and that you can use to quickly and easily test the quality of the air you are breathing.

Even when I was a kid, I remember wondering about the possibility of running out of oxygen when my bedroom door was closed at night. This may not be something you’ve thought about before, but CO₂ is an odorless and colorless gas that we exhale with every breath. The problem is that humans cannot detect elevated CO₂ levels in the air by themselves, which is why we need sensors to do the job for us.

While CO₂ is not harmful at normal quantities, high levels of the gas can replace oxygen in the blood and impact how well we feel and how well we think. According to the CO₂GO website, the CO₂ levels commonly found in offices and meeting rooms may cause people to feel tired and indecisive or suffer from a loss of concentration. Higher CO₂ levels can cause dizziness and headaches, and that’s just the start of your problems.

The reason the guys and gals at Infineon are so happy about CO₂GO is that it boasts one of their XENSIV sensors, which are used to sense the world in automotive, industrial, and commercial markets. In the case of the CO₂GO, we are talking about one of Infineon’s disruptive high-performance C0₂ sensors, which are based on photoacoustic spectroscopy (PAS).

To be honest, this technology was a new one on me, but I had a quick Google while no one was looking, ending up at the Wikipedia, which informs me that, “Photoacoustic spectroscopy is the measurement of the effect of absorbed electromagnetic energy (particularly of light) on matter by means of acoustic detection.” Wow! Who would have thunk?

Reading on, we discover that, “A photoacoustic spectrum of a sample can be recorded by measuring the sound at different wavelengths of the light. This spectrum can be used to identify the absorbing components of the sample. The photoacoustic effect can be used to study solids, liquids, and gases.”

One thing that really blew my socks off (metaphorically speaking) was when I read that, “The discovery of the photoacoustic effect dates to 1880 when Alexander Graham Bell showed that thin discs emitted sound when exposed to a beam of sunlight that was rapidly interrupted with a rotating slotted disk.” Give me strength! Is there anything the ancients didn’t discover?

Even without an associated app, you can power your CO₂GO by connecting it to a USB port, in which case LEDs behind a small window display Green (<500 to 800 ppm = no health risks), Yellow (801 to 1600 ppm = moderate health risks), or Red (1601 to 5000> ppm = serious health risks).

More detailed and finer-grained data can be obtained using the apps that are available for PCs and smartphones (the website shows downloads only for the PC Desktop App and for the iPhone, so I’m not sure about Androids).

The screenshot presented here is from the Desktop App running on the PC in my office. The graphical portion of this image commences around 5:27 p.m. yesterday evening, which is when I plugged my CO₂GO in just before heading home. As we see, at this start time, the CO₂ in my office was around 700 ppm, which is OK but not great. The CO₂ gradually fell overnight, but it quickly ramped up when I entered my office at 9:00 a.m. this morning, after which it remained hovering around the 700 ppm mark, apart from a taking a dive around 12:00 noon when I popped out for lunch with my friend Bob (pronounced the usual way with a silent ‘Q’). Based on these results, I’m going to start leaving the door to my office open and use a fan to bring some fresher air in.

Chatting with my friends at Infineon, I’m delighted to discover that they are planning on adding other harmful gases in their next generation devices. They haven’t confirmed which gases, but CO (carbon monoxide) is definitely a strong contender. It may even be possible to detect multiple gasses with a single sensor, although no one is making any promises at this time.

Personally, I think it won’t be too long before all of these sensors are embedded in our smartphones, thereby allowing everyone to be informed if there are any problems with the air they are breathing. Meanwhile, I am very happy having my CO₂GO monitoring the air here in my office. How about you? Could you be tempted to splash the cash for one of these little scamps?