Wow. That’s fast. My average is more like a month. Maybe even more.
I got my second TA-8133 luxmeter in today (the type with the extra digit). From a different seller, frank hu’s store this time ( https://www.aliexpress.com/item/Handheld-Split-200-2000-20000-200000-LUX-RANG-digital-light-meter-photometer-brightness-meter-photometer-tester/32379016551.html?spm=a2g0s.9042311.0.0.558a4c4dRXGXDo )
My and most reader’s theory was that when developing the TA-8133 after they made the TA-8132 first, they did the downgrading too so all TA-8133 must be bad.
But no, that would make way too much sense, this is China so logic is completely absent: this copy is of the same build as the good quality TA-8132 that took part in the test of the OP. So it has the red top, neatly coiled telephone wire, matted and bigger sensor-diffuser, etc. So the downgrading is not type-related, you may even order a TA-8132 and get a bad one 
And it works well too, the calibration seems pretty close (looks even like within 0.5% for the warm high CRI light in the video (the Mobilux reads 3.4% low)) and reads right down to zero in a nice and stable way.
I did not tell it before but in contrast to this, the cheaped-out version has a faulty calibration (probably because the optical filter was already loose while calibrating), but worse: it stops reading below 24 lux, everything below that is zero. Pretty useful that extra digit :person_facepalming:
Wow that 8133 sucks, but I like how close the 8132 is to being correct 
They are both 8133!! The left one is the latest one that I got in the mail today, the right one is the one dissected in the second post.
Btw, I watched a few youtube video’s about luxmeters (among which a nice one from Big Clive), some show a teardown of the sensor unit and that “good type” sensor as shown in post#2 has been around for a while and can be found in almost all types of cheap Tasi meters, and also other brands.
It is luxmeter investigation night!
I opened the Uni-T UT382, the one with the terrible spectral response, to see if some optical filter was shifted or what, but it was all different inside: (first let’s ignore the dirt on and around the sensor :weary: ) Uni-T went a different direction and decided not to use a separate silicon sensor plus optical filter, but use an all-in-one ambient light sensor, similar to what you find in your phone. No separate optical filter needed.
And that explains the very low performance, ambient light sensors usually have terrible spectral responses (which is why a luxmeter app does not stand a chance changing your phone into a half decent luxmeter).
I tried for half an hour to find this specific light sensor, and I may have found it: it could be a Renesas ISL29020 light sensor. I could not find a photo of this specific one but I found a picture of another Renesas light sensor that looks almost the same:
In the datasheet of the ISL29020 the bond wire layout looks correct, and it has a slightly recognisable spectral response :person_facepalming:
Oooh I see! My bad I got confused, thought you were comparing the new 8133 to the 8132 we knew was good.
So maybe that crappy 8133 you got was just a really old production version or something, some retailers have stock that is many years old.
I would like to assume that they improved the production quality rather than made it worse.
So that means there’s a chance of getting an old crappy unit of both 8133 or 8132 depending on where you buy from.
At least it’s easy to tell which meter is good or bad simply from the appearance
Thanks Djozz,
So Uni-T UT382 is bad despite price?
Djozz his cheaper brother UNI-T UT383 works fantastic for me… But only when I turn out to FC readout where I get easier readout (3 or 4 digits depending on light), and not only easier readout it seems that it is more accurate with FC readout also…
So I don’t know weather is possible that lux meter craps out when processing LUX (more digits) versus FC (less digits). I don’t know how and explain why but my Unit-T UT383 is simply better when I am doing measurements of performing lights(250 kcd + lights) with FC readout.
Will you also test the TA8134?
Maybe you could make a picture from both TA8133 side by side with open sensor So its easy to see that they are not the same internaly. Would be interesting to contact Tasi and get a answere if the crappy one is the new or old version. If they answere at all! But the picture would help to bridge the language barrier.
Not interested in buying one if i have a 50% chance to get a scrappy Meter. But i am willing to ask my way through their support :smiling_imp:
I’m not really on an active mission improving the manufacturers. If my information gets so widespread (not likely, even here these luxmeter posts do not get many reads :partying_face: ) that customers and manufacturers take notice and make better stuff, I will be very happy, but I’m not going to contact them about them.
Atm, I’m not planning more luxmeter tests, that said I do not expect extreme different performance of the TA8134, mostly a different housing I guess.
Thanks for this valuable info! The Extech looks good!
I have a TA8133 from an other seller waiting for the end of the hollydays in some chinese warehouse ;-)
Will tell you what i find when it'll be here. (fingers crossed)
I only wanted to ask them what i get when i order from them. Is the crappy one the old version and they upgraded to the better design. Or have they rebuild the good ones and now are selling a version nowbody wants.
I am not trying to change/help/work with them. I only would like to know if its woth to spend my money. So i would ask. But language is a problem contacting Chinese companys. A picture often says more than 1000 words. Here you are showing the TA8132/33. Is it the same with the crappy TA8133 and the good one? If yes this picture would be good enough!
I just checked the sensor of my latest (“good”) 8133 and it looks almost like the “good” 8132, but the rim of the sensor is different, so yet a different version, although in details. Would this different sensor be related to the better resolution at low light? Nah, that would sound like reason, they probably use whatever component is available at the time of production, sometimes this one, sometimes another. 
Thanks djozz! Mail is out and i will post the result when/if i get a answere!
Update from TASI:
They told me that the version with the bad sensor is the old version. And they are not selling this version anymore (they wanted to know when and from which shop the old ones was bought).
They also said:
You can buy directly from us, we are the manufacturer, we can assure you our quality. Please don’t worry about the sensor we will send you our updated new product (USD17/PC).
So it seems the new Meters should be with the good Sensor ( But aslong you are not buying directly from TASI you can not be sure to get the new one).
That is a surprising outcome to me, in principle encouraging but time will tell if that is indeed the case.
Thanks Docc for contacting Tasi, even if it is not true what they say it helps if manufacturers know that their customers notice and care about the build quality of their products, which is not obvious in case of luxmeters.
I also hope that it is the truth! I not only asked which one i get i also linked the test so they know it is not only one person asking. And that many more people will be aware of their answers.
I asked how much shipping will cost (and ~shipping costs for the bigger countries). If it is not to much (compared to buying on Aliexpress) i will order one directly from TASI. Then we will see which one they deliver. I also asked if they sell directly on Aliexpress (could not find them on Ali).
As I predicted, the bad one was probably an older lower quality version.
Let’s see if buying directly from them gives you the new one.
Good thing it’s easy to tell which is which.
Thanks for the info
Ok i was expecting to pay a bit more than on Aliexpress. But a total price of 47$ inkl shipping is a little bit to much for my taste (cheapest price on Aliexpress is less than 19$ inkl. shipping.
I think we will have to wait and see what we will get from Aliexpress when the Sellers old stock is sold and new ones are orderd from Tasi.
@ Djozz
Is there any difference in labeling on the two 8133? Something we can ask the Seller before we order (except the red cap at the top)?