co2 sensors to measure co2 levels in a car

GSS Analyse CO2 In Car Journeys

Ever wondered why long car journeys make you feel tired and sleepy? Is it the boredom of endless, never changing motorways or perhaps something else? Carbon Dioxide sensor specialists, Gas Sensing Solutions, wondered if it could be a build-up of CO2 gas, because at levels of 1000 ppm and above people can become drowsy and lethargic. So they took a CO2 datalogger from their gas sensor range on a road trip to find out how CO2 levels changed throughout the journey.

co2 sensors to measure co2 levels in a car

Why can car journeys make you feel sleepy?

Dr David Moodie, Technical Manager at GSS, explained, “This follows on from our trip to Asia where we used our CO2 datalogger to measure CO2 gas levels on planes, trains and taxis. We were surprised that levels were the worst in taxis – peaking at an astonishing 10000 ppm on one journey – so we decided to check the levels on our own road trip in the UK.”

datalogger to measure co2 in a car

Measure CO2, temperature & humidity in a car

Before the datalogger took to the road, it was first used to test CO2 levels in a stationary car. This would show the impact on CO2 levels with a group of 4 people in a confined space. The engine was switched off and the windows kept closed to avoid any flow of fresh air inside the vehicle. The datalogger showed that when the passengers got inside the car, the CO2 level was 1000 ppm. It then rocketed to almost 4000 ppm in just 15 minutes. At that stage, the atmosphere inside the cabin had become extremely stuffy and unpleasant.

Graph showing CO2 levels in a stationary car

Graph showing CO2 levels in a stationary car

Next came the road trip. The first car journey involved two people travelling to the supermarket. The CO2 from their exhaled breath increased the concentration of CO2 in the car cabin to around 1400 ppm. Surprisingly, it only took about forty-five minutes to reach this level, which shows how quickly CO2 levels can rise. The datalogger was then left in the car overnight with the windows closed. The graph shows just how long it takes for the CO2 to disperse from a closed car, taking until around 9am the next day to drop down to nearer ambient levels of CO2.

graph showing CO2 levels in car recorded with a datalogger

CO2 levels recorded with a datalogger

The second car journey recorded four people travelling non-stop from Wales to Scotland. With four people, the level of CO2 shot up even faster, reaching 2000 ppm in about twenty minutes. This is the level where CO2 symptoms can start to cause loss of concentration, headaches and sleepiness for example. Fortunately, they opened the windows to bring in fresh air from outside, which reduced the CO2 to more acceptable, ambient levels within an hour.

Dr David Moodie, added, “Our real-world datalogger measurements show how CO2 levels can rapidly build up in an enclosed space with several occupants – and in a relatively short space of time too.  The results on both journeys exceeded The World Health Organisation* guideline that CO2 levels should be below 1000 ppm.” 

Datalogger details

The datalogger used in the experiment measures CO2 concentration, air pressure and temperature, along with relative humidity every few minutes. This unit was designed and built by GSS and it uses one of its low power, ambient air, CozIR®-A sensors. GSS’s unique LED technology at the heart of its sensors means that it has a very low power consumption, unlike many other CO2 sensors that need mains power. This enables battery-powered CO2 monitoring products to be created, such as this datalogger, that is able to record over a 2-week period without needing a change of battery.

co2 datalogger for measuring co2 levels

GSS CO2 datalogger with a CozIR sensor inside

Dr David Moodie, concluded, “This ability to be battery powered for long periods has opened up a whole new range of design possibilities for CO2 monitors. Now it’s possible to have handheld breath monitors with high speed sensing for people with respiratory conditions, portable leak detection instruments, handheld MAP analysers, and wireless air quality monitors for IoT applications. These are just a few examples of what is achievable, the possibilities really are endless.”

Drowsy driving facts and stats

According to a 2005 poll by the American National Sleep Foundation, 60% of adult US drivers – about 168 million people – said that they have driven a vehicle while feeling drowsy in the past year. More than one-third, (37% or 103 million people), have actually fallen asleep at the wheel. Of those who have nodded off, 13% say they have done so at least once a month. According to data from Australia, England, Finland, and other European nations, drowsy driving represents 10 to 30 percent of all crashes. More details at http://drowsydriving.org/about/facts-and-stats/ and https://www.sleepfoundation.org/sleep-topics/drowsy-driving

A paper on ‘Modelling CO2 concentrations in vehicle cabins’, which focusses on the build-up of CO2, can be found at: https://www.engr.ucr.edu/~heejung/publications/2013-CO2-model.pdf

In an article entitled ‘The Drowsy Driving Off Switch’, Air Quality Consultant Dale Walsh found that recycling the air in a car cabin causes CO2 levels to rise rapidly. In his experiment, it took an hour for a level of 2500 ppm to be reached when recycling the air with only one occupant in the car. The article is available at: https://www.americanasafety.com/associates/docs/publications/The%20Drowsy%20Driving%20Off%20Switch.pdf

Data: the big trend in MAP

By Joanna Sampson: Gasworld – https://www.gasworld.com/data-the-big-trend-in-map/2015275.article

Modified atmosphere packaging (MAP) is defined as ‘the packaging of a perishable product in an atmosphere which has been modified so that its composition is other than that of air’ (Hintlian and Hotchkiss, 1986).

It is one of the most updated options to traditional packaging technologies and involves removing and replacing the atmospheric gases with a predetermined gas mixture to slow down the product aging process and preserve the fresh colour, taste and nutrient content throughout an extended shelf life.

The three main gases used in this process are oxygen, carbon dioxide and nitrogen. The choice of gas or mixture of gases is very dependent upon the food product being packed.

MAP analyser technologies, which the special feature in gasworld’s Global September issue is looking at, are used for quality assurance in packaging under modified atmosphere.

But what are the key trends driving this industry at the moment?

gasworld spoke to AGC Instruments, Gas Sensing Solutions, MOCON Europe and WITT-Gasetechnik, who all said how data is being collected and stored is the most important trend they are seeing.

MAP CO2 Sensor

Modified atmosphere packaging (MAP)

Source: MOCON Europe

“There seems to be a high focus and demand for collecting and storing data. Hereby enabling producers to improve their productivity and offer improved quality as well as extended traceability to the customers,” said Morten Torngaard, Sales Manager at MOCON Europe.

Mike Loughnane, AGC Instrument’s Business Development Manager, added, “The ability to log and save data and effortlessly send this to a database is probably the most important trend. Audits are becoming increasingly rigorous and food producers must show a ‘paperwork trail’ where this is now stored in computers as opposed to the traditional paper files which are environmentally unfriendly and space prohibitive. Real time data that is easily accessed on computers is a means of monitoring operations in large food production environments.”

WITT-Gasetechnik’s Head of Marketing Alexander Kamschulte echoed, “The documentation of processes and quality assurance is becoming increasingly important. For this reason, we have already equipped our devices with export interfaces and wireless technologies such as Bluetooth or WLAN.”

“The demand for these things will continue to increase. Especially for larger food producers we expect an increasing importance of inline analysers during the packaging process. This, in conjunction with sample testing offers maximum process reliability and documents highest quality standard to the customers.”

gasworld will publish the full feature, titled ’In focus… MAP analyser technologies’, in its upcoming Global September 2018 edition.

co2 sensors for refrigeration applications

GSS Targets Growing CO2 Refrigerant Market

Gas Sensing Solutions (GSS), a leader in CO2 sensor technology, has announced that it is targeting the growing market of CO2 refrigeration systems with its award-winning CO2 sensors.

A century ago, CO2 was commonly used as a refrigerant, but had practically disappeared by the 1950s with the use of other gases such as HVFC, CFC and HFC.1 The air conditioning and refrigeration industry has now been urged to move to more “natural” refrigerants like CO2, with the onset of huge price increases for traditional HFCs.2 The reduction of harmful greenhouse gases is also a key consideration, as these traditional gases contribute up to four thousand times more than CO2 to global warming.3

co2 sensors for refrigeration applications

Measuring CO2 levels in refrigeration applications

Dr David Moodie, Technical Manager at GSS, said, “CO2-based water chillers, chest freezers, beverage coolers and heat pumps are increasingly being developed and commercialised, making this a very exciting new market for us as providers of innovative CO2 sensors.4 For example, CO2-based refrigeration systems are in use in a large number of Swedish supermarkets, with other countries following this trend towards a highly green refrigeration solution.”5

It is important to have CO2 sensors in this application to monitor for potential CO2 leaks. CO2 exists in the atmosphere, and background (normal) outdoor air levels are around 250-350 ppm.6 CO2 is harmless to humans, except when concentrations are four to five times greater than normal. For example, at 2000-5000 ppm, health problems such as headaches, loss of attention and slight nausea may be experienced.7 As CO2 gas is odourless and colourless, leaks could easily go unnoticed. A speedy warning of increased CO2 levels is therefore vital in ensuring people’s safety in CO2 refrigeration applications.

GSS has a range of standard CO2 sensors for refrigeration applications. The ExplorIR®-W is a particularly robust design, built with mid-infrared LED technology at its core. It’s this solid-state technology that enables the earliest warning of any possible CO2 leaks. This also provides the required long lifetime and high precision needed in leak detection applications.

Available with an extended temperature range, the ExplorIR®-W can operate right down to -25º C as required in many supermarket freezers. It is available in measurement ranges of 0-5%, 0-20% and 0-100% CO2 concentrations according to the specific application. The sensor can be adapted for special requirements, or developed into a custom CO2 sensor solution for leak detection applications.

  1. https://www.hpacmag.com/features/co2-gets-a-second-life/
  2. https://www.coolingpost.com/uk-news/co2-refrigerant-faces-supply-issues/
  3. http://www.refrigerantsnaturally.com/
  4. https://www.sintef.no/globalassets/project/creativ/publications/journal-and-conference/d4.1.6–keynote_gl2010_neksawalnumhafner-co2-arefrigerantfromthepastwithprospectsofbeing1.pdf
  5. https://www.diva-portal.org/smash/get/diva2:488463/FULLTEXT02.pdf
  6. https://ohsonline.com/articles/2016/04/01/carbon-dioxide-detection-and-indoor-air-quality-control.aspx
  7. https://ohsonline.com/articles/2016/04/01/carbon-dioxide-detection-and-indoor-air-quality-control.aspx