Home Forum Hardware VOC capabilities

This topic contains 4 replies, has 2 voices, and was last updated by  Cane 1 year, 2 months ago.

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    Hello, I am wondering about the capabilities of measuring VOC’s. I haven’t kept up with the development, but I guess we are talking about the BME680 chip.
    It is a very important thing for me, since I am suffering from MCS (Multiple Chemical Sensitivities). Even small amounts (way below what any normal human being would be able to sense or should be affected by) makes me sick.
    Since I got this problem 2,5 years ago, my olfaction system, have become 5-6 times more sensitive to certain smells (but not all). Having said that, there are a lot of things that don’t even registers as a smell, but it still makes me sick. Sometimes, as low as 10s exposure is enough (that’s from breathing, my eyes are even more sensitive to exposure).

    So my question is, can the uRADMonitor measure individual types of VOC and if so, witch ones? How long time does it take to make a measure? Can it measure multiple at the same time? Specifics, since over all number of VOC’s might not give a good indication if it is more dangerous. In the long run it will of course, but that train have passed, I have already become sick by chemical exposure (that’s how it all started). Now it is a matter of avoiding those that “I know” (I first have to analyze the sources that make me sick, to find out what types of VOC is causing it) makes me sick. Because it is no fun, having all energy drained out of you because of a minute of exposure… it can make me sick for days and it can take weeks, for the body to recover. During that time, I get more sensitive. Meaning that what used to take 10 minutes, takes 7 minutes, then 5 etc.
    A mobile phone is a perfect example. When I am at my best, then I can stand it for 10 minutes at a time, multiple times a day, before even noticing anything. But when I am at my worst, I get sick from 10s exposure.

    Perfect scenario would be to more or less, always monitor for the ones that I am most sensitive for (when I know witch ones those are) and cycle through others with less frequency (in the order that I can stand them). If my body can take 5 minute of exposure to something, it might have to take a measure every minute,and if my body can stand 30 minute exposure of something, then it might only need to monitor every 5 minutes to be safe…
    Safety might be, enough time to walk away, close the window etc.



    I totally forgot a crucial point in the discussion. As already mentioned, a phone can make me sick. The problem is when electronics get heated, because there are a lot of chemicals in electronic parts, and then VOC’s gets released… If the uRADMonitor gets hot, then I won’t be able to carry it around with me, witch would be ideal. But being able to monitor the air, outside my home is still beneficiary. There are multiple laundry rooms in the area, houses burning fuel for heating, people barbecuing in the summer (lighter fluid is one of the worst things) etc

    Not all electronics does heat up. I often use headphones and a Bluetooth adapter (I need to be a minimum distance of 2 meters from the phone, to not be affected by it), and I have never had any problems with it.


    Radu Motisan

    Hello Cane,

    Sorry to hear about your health issues.

    The BME680 is a mems sensor, but for detecting VOC it operates on the same principle like any other semiconductor / metal oxide sensor. Read on that here: http://www.edaphic.com.au/gas-detection-encyclopedia/semiconductor-sensors/
    The sensor initiates REDOX chemical reactions on a heated filament, resulting in ionised local air and as a result modified electrical resistance. A cleaner air will produce less such reactions, resulting in poor conductivity and increased resistance, while a polluted air will increase conductivity resulting in lower resistance.

    Given the existence of many different gases / vapours / chemicals, any ppm would be an approximation for a particular class of substances. Their molar mass / burn rate / ionising resulting compounds and multiple other properties and complicated chemistry, make it impossible to compute an absolute ppm level, or to identify the substances.

    On the other hand it offers a clear indication of changes in the air composition, and since the uRADMonitor records all data online, you have access to a history chart and you can correlate that to your condition. It will help you link the numbers to various emissions and their effect on your health.

    Please have a look on the uRADMonitor A3, here. There is also the uRADMonitor INDUSTRIAL, that has 4 slots where we can install 4 sensors for 4 different gases, there’s a big list at the bottom, see it here.



    Thanks for your reply. I am not certain that it will work, if it can’t identify the substances.

    Is it only the industrial version that can have different sensors? Are they expensive, or is it possible to exchange them step by step, if I where to narrow things down?

    There was a time, when I used a very good 3M Full-face respirator (gas mask). When I used it with the “3M™ Gas, Vapour and Particulate Filter, A2B2E2K2HgP3 R + Formaldehyde, 6099” filter (6099, is kind of the best of the best of their filters), then I was safe. So I know that I don’t have to try to find VOC, that isn’t blocked by it.

    The information is as follows:
    3M™Gas, Vapour and Particulate Filter 6099 protect against organic vapours (boiling point above 65 °C) inorganic vapours, acid gases, ammonia and its derivatives, mercury, formaldehyde up to 10ppm and particulates. Filter capacity Class 2 – medium capacity, up to 5000ppm.
    There is a specific list of substances and to what level, the filter protects against it, but I haven’t been able to find it right now.

    I can tell you that it was very exhausting to breath through it, so I did try the ABEK1+P3 filter, instead of the ABEK2P3 filter previously mentioned. But it didn’t work. It gave me, no protection what so ever… If I could have afforded it, I would have bought a fan powered unit. But now it doesn’t matter anymore, since I react to a certain type of rubber used for the valves in the mask.



    My idea was to measure the background VOC, and the introducing one product at a time. Measure the difference and when I have a lot of different measures, then I could compare and see if there are similar substances in the products that I react to, then I am more likely to be sensitive to them.

    That’s kind of, how I was able to find out that I react to artificial sweeteners (sugar alcohols). The only common denominator in a lot of oral hygiene products, that I reacted to, was Sorbitol…

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