I have only been able to verify the existence of the previous ones<\/strong>.<\/p>\n\n\n\nI will be adding to this article with new variants as they appear.<\/p>\n\n\n\n
If you have a different sensor, tell us about it in the comments.<\/strong><\/p>\n\n\n\nHow do I avoid buying a fake sensor?<\/h2>\n\n\n\n Although not foolproof, there are a few tips that can help you reduce the chance of receiving a fake sensor.<\/p>\n\n\n\n
If the price is too good, the sensor is probably not that good. At the moment, such a sensor should cost you between 18 and 22 euros (they have gone up a bit lately, I guess as a result of high demand).<\/li> You will have a better chance that the sensor is original if you see that customers have posted pictures, when making their reviews, and in those pictures you can see that they have the green plate and embossing on the case.<\/li> Check that the reviews are good and that the customers do not say that the sensor is fake (not all reviews can always be five stars, and this is normal). If they say that the sensor is fake, it is better if they accompany it with a photograph (there are people who have had problems with their project and blame it on the sensor being fake or faulty, and it doesn't have to be that).<\/li> Make sure the seller has some seniority, and that their overall rating is good. I usually assume that an overall rating above 97% is good enough to give me confidence.<\/li><\/ul>\n\n\n\nHow do I return an MH-Z19B sensor bought on AliExpress?<\/h2>\n\n\n\n If you have received a fake sensor, you will have to open a dispute on AliExpress to get your money back.<\/p>\n\n\n\n
There are two reasons why you can ask for your money back:<\/p>\n\n\n\n
The sensor is false<\/strong><\/li>The sensor does not work<\/strong> correctly<\/li><\/ul>\n\n\n\nMy suggestion, because It has worked well for me<\/strong>is that you select as a reason that the sensor is not working properly, but that you make it very clear in the description that, in addition<\/span>the sensor is not working properly<\/strong>.<\/p>\n\n\n\nDepending on your particular case, you will have to use your own weapons. I used the comparison with two other sensors I had previously.<\/p>\n\n\n\n
The message I used to open the dispute is as follows:<\/p>\n\n\n\n
\"Measurements are unusable This is reporting a CO2 concentration 1266 PPM. Next to it a real MH-Z19B and a Senseair S8 LP are reading 2419 PPM and 2389 PPM respectively. Attached photos of received product (black PCB, RoHS is missing, Pins are labelled differently and a different physical connection to the one offered). Attached is a video with the full unboxing and explanation. More information and explanation here: https:\/\/revspace.nl\/MH-Z19B#Fake_MH-Z19B_.28black_PCB.29\"<\/em><\/p>\n\n\n\nAlong with the text, I have sent the following pictures of the sensor received:<\/p>\n\n\n\nIn addition, I have sent a video of the unpacking of the product, in which you can clearly see the shipping label<\/strong> (this is very important for AliExpress<\/strong>Here you will see it with that part blurred for privacy) and the explanation of the comparison.<\/p>\n\n\n\nAt less than 24 hours<\/strong> I had a reply from AliExpress, agreeing with me<\/strong> and telling me that I would get the money back on the same card with which I had paid for it.<\/strong> and that did not need to send the product back<\/strong>.<\/p>\n\n\n\nBut beware, I was not given a reason why the product was fake.<\/strong> (which was what I had claimed), but because the product was not working properly<\/strong>.<\/p>\n\n\n\nThis means that, if you cannot prove that the sensor is malfunctioning<\/strong> (as did I, who had two other sensors to compare with and the means to document it in a video). maybe it's not so easy to be proved right<\/strong>. This is something you will have to rate <\/strong>in order to steer your dispute in one direction or the other.<\/p>\n\n\n\nThe video I have sent is, at its core, practically just like the video below<\/strong>without the central explanation of what a fake sensor is, and very summarised (1:30 of unboxing and 3:45 of measurements and comparisons and with a basic, much simpler editing). I also took the time to subtitle the whole video in English<\/strong>.<\/p>\n\n\n\nHow do I return an MH-Z19B sensor purchased on Amazon?<\/h2>\n\n\n\n Yes, buying from Amazon is more expensive than buying directly from China, but, in addition to the fact that it is usually more expensive to buy from Amazon, it is also more expensive to buy from China. you receive it much sooner<\/strong>has the great advantage that returning a product is extremely easy<\/strong>.<\/p>\n\n\n\nIn this case, as I see it, you have three options:<\/p>\n\n\n\n
Return it to because it is<\/strong>without further explanation<\/li>Return it to because it is false<\/strong><\/li>Return it to because it doesn't work<\/strong><\/li><\/ol>\n\n\n\nThe difference between the first option and the other two is that, in the first case, you have to pay the return costs yourself.<\/strong>The other two cases will be free of charge for you.<\/p>\n\n\n\nOn Amazon you can return<\/strong> (at your own expense for return shipping) of any item purchased for a period of 30 days<\/strong>unless otherwise stated.<\/p>\n\n\n\nIn cases where the return is due to the fact that the product does not work, is not as advertised<\/strong>etc. you do not have to pay return postage<\/strong>.<\/p>\n\n\n\nThis means that it is better to try to return the product. claiming that it is a fake and does not work properly and, only in the event that they do not agree with you, return it because if<\/strong>even if you have to pay the shipping costs yourself.<\/p>\n\n\n\nThe return shipping costs, in cases where you have to pay for them yourself, are 2,99 if you hand it in <\/strong>at a post office or a Celeritas office or a 5,50 \u20ac if you ask for home collection<\/strong>.<\/p>\n\n\n\nIn any case, if you bought the sensor on Amazon, you are guaranteed to get a refund<\/strong>.<\/p>\n\n\n\nMH-Z19B dummy sensor on video, full explanation, tests and data<\/h2>\n\n\n\n In this video you can find additional information about the MH-Z19B dummy sensors with explanation, measurements, graphs, comparisons, etc. <\/p>\n\n\n\n