Test Breath Ketones without a Ketonix (using a cheap breathalyzer)

ketonix
acetone
breath
(A ham loving ham! - VA6KD) #41

I think the sensor is a TGS822: https://www.soselectronic.com/products/figaro/tgs-822-7719 This sensor specifically detects alcohols and other solvent gasses (acetone).

You can find them on eBay for around $6USD for quantity of 1. They need to be coupled to a humidity sensor as their output is biased by the humidity level at the time of the sample. Someone’s already tried it with an Arduino module: https://jenslabs.com/2013/06/06/ketosense-an-arduino-based-ketosis-detector/

There are several other models of sensors in the same family, but no others that I can find detect solvent gases.

#42

Sorry, but again I no longer think this question is open. I understand the ketonix does 3 light levels of 10 intervals. A total of 30 intervals. The cheap breathalyzer in mg/L works at .01 intervals, where 0.30 is high and 0.01 is low, so again 30 intervals.

A breathalyzer, by necessity, must have at least this many levels. Anything more refined would be too easily susceptible to technique of use. Actually as far as I can tell (by the accounts) the ketonix is far more susceptible to technique than the $2 breathalyzer.

#43

Thanks for that link. A shame the guy didn’t know more about ketosis. Interesting that he found a correlation between the ketostix and the breathalyzer. That’s what we’ve been wondering here.

More data needed. @Daisy did you find where that data was? Can you hint me where to search on the forum?

#44

The newer (2015 and onward models) ones may actually show more intervals when linked up to the software. I don’t know, I don’t have them.

Regardless, even for the old, the question is still open. It doesn’t matter if the breathalyzers have more intervals if it generates those intervals less precisely (in terms of accuracy). Even various blood ketone meters are known for having differences in precision. One may consistantly and properly show .5 mmol, while another may show anywhere from .02 - 2.1 (as an example) when taken 3 times in a row with none matching.

So, the question remains open, can we depend on the readout of the cheap breathalyzer to indicate anything more than the presence of ketones in the breath (in other words, to say whether in some level of ketosis, whatever it may be), or can we actually reasonably rely on it’s readouts correlating (at least decently) to blood ketone levels, so that we know, say, between .07 and .09 BAC is around 1 mmol that we’d find in a blood ketone analyzer (or whatever it may be)? The Ketonix may still be better in that regard, or it may not, there hasn’t been much to show either way yet.

#45

I see no reason to say the cheaper models are less accurate. It’s a perfectly testable thing. It’s too early for me to comment on the accuracy of my model. I think in all likelihood they use the same sensor.

The breathalyzer I have always shows the same reading on repeated testing. That’s not what I hear about the ketonix. By all accounts the ketonix does not do this.

So, in terms of which device we should speculate about the accuracy of I think we would be better to point the finger at the recently developed ketonix, not the decades old tech of the breathalyzer, which has in all likelihood had it’s kinks ironed out a long time ago.

Are people complaining about the accuracy of the new ketonix as much as they did about the old one?

#46

Yea, I’m not saying the ketonix necessarily is better in that regard. I’m saying the question is still open and any speculations as to which is better in that regard is, at the moment, just that.

#47

I think it might be good to open yourself to the possibility also that the ketonix is possibly worse. So far, all we have to go on is user reports. Going by those, the ketonix is less reliable.

#48

Oh, I’m open to that. I’m actually hoping that is the case (saving money is a big deal to me, and I’ve been contemplating getting a new ketonix but costs have been prohibitive. If I can get a better one for less than $20, I’ll be very happy). I’m just saying the question remains open until we can get more testing, data and insight.

#49

Awesome. Well, since they’re so cheap, why not buy a breathalyzer and do some experimenting with us here? It’s only a $5 - $15 outlay… and it’s especially useful coming from you because you would own both devices.

#50

I was thinking of doing so, I just don’t have time yet and don’t know where my ketonix is. Might be able to find it this weekend sometime though.

Of course, the better tests would come from those that can compare against blood ketone meters, as that’s really what we are looking for (correlations between breath levels and blood levels). I don’t have one of those, unfortunately (that’s even more expensive in the long run, which was why I went with the ketonix to begin with).

#51

Ideally we’d have all 3 in order to establish actual data and confirm reliability. However, 2 meters might be good enough to establish a comparative reliability. I’d be excited to hear your comparative results if you do it.

(Chris W) #52

The new Ketonix USB (2017) reports reports Acetone in PPM when linked to a computer. The flashing lights aspect is primarily designed for for portable use when you do not have access to a computer. I find the Ketonix to be quite useful, but it also requires a bit of technique for consistency. The technique needed would be difficult for my wife as she is prone to asthma attacks and I worry that exhaling that much beyond a normal exhale would trigger an attack for her

At Low-Carb Breckenridge, there was another ketosis meter (LEVL) being demonstrated which did not require as much of a special technique and it was very nicely packaged, but it was quite a bit more expensive than the Ketonix and requires that the moderately expensive sensor pack be replaced periodically. :expressionless:

Michel, the inventor of Ketonix presented at Low-Carb Breckenridge and specifically discussed blood vs. breath ketones. In a nutshell, he showed that the blood and breath meters are measuring at different points in the metabolic process and that there would be times that they would not correlate to each other. What I took away from the presentation was that acetone in the breath is a more direct indicator that you are actively burning fat. Hopefully his presentation will be posted soon on the Low-Carb Down Under Youtube channel.

#53

thanks @cwstnsko ! That’s all good to know.

That could just be a conversion from mg/L to PPM, though it does sound promising. What would be good to know is the precision units (or intervals).

[update: PPM and mg/L are identical, so no conversion required. My breathalyzer also reports mg/L so it’s not a point of difference between a breathalyzer and a ketonix. I’d be surprised if even the new ketonix has a higher precision than a standard breathalyzer, but I wait to be corrected.]

I look forward to seeing his presentation. I don’t understand how acetone in the breath (a waste product and also the breakdown product of the more desirable BHB ketone bodies) would more accurately indicate fat burning than directly measuring BHB ketone bodies in the blood (a living fuel situation). Do you remember enough to explain?

(Chris W) #54

It would seem odd that there would be no conversion required between the inexpensive breathalyzer (mg/l) and the Ketonix in PPM since the Ketonix Charts from the owners manual consider beneficial nutritional ketosis to start around 4 ppm, and the breathalyzers seem to read in the hundredths (0.05) of a mg/L. unless I’m interpreting what I see above incorrectly.

A link to Michel’s video from the 2016 Lo-Carb Vail is Here
It is not as specific in regard to the differences as the 2017 presentation, but he does get into some of the differences from about 9:30 to about 13:00 in the video.
What I recall from his 2017 presentation was that the blood test does reflect the availability of the ketones for fuel, but not whether they are being USED for fuel at the moment. Some of the conditions I recall him mentioning where

  1. blood ketones available, but not being used for fuel (perhaps because of the presence of glucose,) result: blood +, breath -
  2. blood ketones available and some being used for fuel. result: blood +, breath +
  3. blood ketones unavailable because they are ALL being used for fuel. blood -, breath +
Low ketone levels in the evening with IF
#55

https://www.google.com.au/search?sclient=psy-ab&q=converting%20ppm%20to%20mg%2FL&=&=&oq=&gs_l=&pbx=1

To convert parts per million to milligrams per liter, use the conversion factor of 1 ppm = 1 mg/L. This means that 1 part per million is equal to 1 milligram per liter.

#56

Thanks for the explanation and the link. I’ve heard that one. I’ll revisit.

(A ham loving ham! - VA6KD) #57

I guess I should have read the manual first for my breathalyzer…Found the following line in the back of the manual:

20170329_210058_crop_742x204.jpg742×204 121 KB

#58

It’s a good thing. That’s what we want from a breathalyser.

(gooeykablooey) #59

@cwstnsko the cheapo breathalyzer may be perfect for your wife then, mine that I paid $2.65 USD for doesn’t require I blow the full 10 seconds. If I’m in ketosis deeply it let’s me know within about 2 seconds with a beep and shows my read out. It continues to run the full 10 seconds but I’ve never gotten a higher reading by continuing to blow the rest of the 10 seconds.

(roxanna) #60

So I got mine in and it’s reading as 0. I eat zero carb so less than 5 total carbs a day. I wonder if it’s because of my protein? I usually take in about 130 protein. I do believe I am in ketosis based on other signals.