Accuracy of SNZB-02D vs SNZB-02

Hi all

I have been using a number of SNZB-02 for a while around the house.

I have now picked up a SNZB-02D to replace one of the SNZB-02.

However, after placing the new SNZB-02D in the same location as a SNZB-02 previously was, I noticed that the Humidity reading on the SNZB-02D was significantly lower. So I placed the SNZB-02 directly next to it to compare measurements between the two devices.

The Temperature measurement between the devices is within normal margins - however there is a significantly difference in the Humidity measurement. The Humidity displayed by the SNZB-02D (top) is around 10% lower than that of the SNZB-02 (bottom). This difference is persistent across several hours.

Which one am I supposed to believe?

None. Both are for home use and are not certified measuring instruments.

@jam3 : Thanks - am aware of that. However, I would still expect a certain degree of accuracy. Otherwise what is the point of such a sensor?

After some googling I found lots of reports that the original SNZB-02 is over-reporting humidity by about 10%.

I placed 2x SNZB-02 and the new SNZB-02Dd next to my Ecowitt sensor to have another reference point in the mix. Here the results:

Device Temperature Humidity
Ecowitt 25.8 ⁰C 52%
SNZB-02D 25.9 ⁰C 50%
SNZB-02 (I) 25.9 ⁰C 61%
SNZB-02 (II) 25.9 ⁰C 59%

The SNZB-02D is within acceptable margins for Humidity compared to the Ecowitt - but both SNZB-02 are way out.

So the original SNZB-02 do not provide reliable Humidity readings.

Everything you wrote about was predictable. For what purpose did you actually start the topic?