So I was very happy how the Tasi TA8132 of the test above performed, so I ordered the 'upgrade' TA8133 on Aliexpress: only 2 dollar more and in the lowest range it has a digit more in the read-out, it shows a tenth of a lux instead of just lux. I did not expect a more accurate sensor but I hoped for a stable enough read-out at the lowest range that the extra digit was meaningful.
It turned out different. I received a completely different luxmeter. It looks the same apart from the extra digit, but if you look closely, everything is different. And I do not know if this is specifically the TA8133 that is completely different from the TA8132, or that the whole TA813x series was overhauled at some point and that you may receive a 'new' TA8132 too if you are unlucky. Let's have a look at the outside:
"Good old" Tasi TA8132 on the left, "downgraded" Tasi TA8133 on the right
You may notice:
*slightly different colour of red
*red top on the left, black top on the right
*different colour LCD display
*more sloppy telephone wire on the right
*larger, slightly matted, and more opaque sensor diffusor on the left
*plastic texture of the sensor is bit different (can not be seen on pic)
This is all unimportant to me but it shows that they completely re-invented this luxmeter, nothing went untouched.
Now the inside of the sensors:
Sorry, reversed now, old TA8132 on the right now, new TA8133 on the left.
*the old type had a loose diffusor precision-aligned with some plastic posts, the new type diffusor is molten down (=not neccessarily worse, but cheaper to make)
*I received the new type TA8133 with something rattling inside the sensor, it appeared to be the optical filter that lived loose in the cavity . It was made press-fit into holes in the circuit board but to the wrongs specs: it had no grip at all when I pressed it back in place, I had to use cellotape to make it stay. After that the reading was completely off, I guess they calibrated it already without filter. The old type TA8132 has a screwed-down optical filter that will not go anywhere.
*the optical filter of the new type is not completely clear, and the sensor is heavily scratched (because of the loose filter going about?). the old type has a clear filter and fairly clean sensor
*the optical filter window of the new type is small and the sensor is well off-center, I fear for the cosinus-response of this luxmeter. The old type has a large window that will not influence the optical path to the diffusor.
*the sensors themselves are not the same type, they are of a different make (I did not remove the optical filter of the tested TA8132 because I fear for altering the calibration, this luxmeter will still be used).
So with different optical lay-out, different diffusor, different optical filter and different sensors, in fact these are completely different luxmeters. I would have to test this TA8133 all over again to see if it is any good. And with everything looking less well done, I fear for less performance as well. But who knows...
Because I'm not sane and despite knowing better, I ordered one more TA8132 and one more TA8133 luxmeter, from different sources to see if these differences are consistent. They probably will dropship from the same source after all but who knows.
China is a weird country..
Edit oct.5, next chapter in post #18