SONOFF SNZB-02 Humidity not not correct

[user1417]

I have (2) SONOFF SNZB-02

No, 1 is reading 77.09 deg, 73% humidity
No. 2 is reading 77.62deg, 71% humidity
As a check meter, I have Acurite
It reading 77,00 deg, 53% humidity

All (3) devices are within 12" apart. They should all ready near the same values

Now my house has 6" open cell foam, my has stays year around in the low 50% humidity range

Acurite is very consistent, in addition, the ODA humidity is in the 40% range today, my cannot be in the 70% humidity range.

Also, living in Louisiana I know what high humidity feels like. We have been having very low humidity.

My question: how can (2) brand new SONOFF SNZB-02 be so far off? I don't think this is a calibration issue.

Your thoughts?

[aaiyar]

@user1417

SONOFF SNZB-02

What kind of accuracy were you anticipating from a $10 sensor?

At least it’s internally consistent.

[user1417]

The temp is accurate.

I just selected a sonoff temp/humidity sensor from the supported hubitat device list. I figured it was approved device that it should work

What should I use? What device really works that is on the approved list?

[aaiyar]

@user1417

from the supported hubitat device list.

FYI, that list makes no claim of sensor sensitivity or accuracy.

The most accurate sensors I’ve had are from ecowitt, but they need the ecowitt gateway to bring them into Hubitat.

[velvetfoot]

@user1417

Acurite is very consistent

Does that equal correct?

Your local weather station probably gives you the relative humidity, right? You said it was 40% today.
Why not bring them all outside and see what they say?

[Hatallica]

Maybe I got a particularly good lot. The salt calibration test was spot on when they were new. Just double-checked and the readings pass the crude "seems to make sense" test.

[bjcowles]

The three I have not thrown away consistently reported 10 to 15% higher than the actual indoor humidity. The good news is @kkossev has included them in his "Tuya Temperature Humidity Illuminance LCD Display with a Clock" driver. Not only can you adjust the offset for humidity, but you can configure the reporting intervals.

[RELEASE] Tuya Temperature Humidity Illuminance LCD Display with a Clock (w/ healthStatus)

Vote for the Linptech Human Presence Sensor with 24G mmWave Radar in the Product of the Year Elevated by Hubitat in 2023 ! This driver can be installed from Hubitat Package Manager, search for "Tuya Temperature Humidity Illuminance LCD Display with a Clock" or by Tag 'Zigbee'. The latest stable version code is here: https://raw.githubusercontent.com/kkossev/Hubitat/main/Drivers/Tuya%20Temperature%20Humidity%20Illuminance%20LCD%20Display%20with%20a%20Clock/Tuya_Temperature_Humidity_Illuminanc…

[lcw731]

I am in the process of retiring all of my Sonof sensors with Ecowitt Wn31's because the Sonoffs were just all over the place (I also benchmark them with an Acurite Hygrometer). Yeah, you need a gateway or display, but the Ecowitt rabbit hole is a fun one to venture down. These Ecowitts have always been dead on with the accurate hygrometer.
While not on the compatible list (which are only devices that have been tested by Hubitat staff), they are indeed compatible with Hubitat using @sburke781 Ecowitt Community Driver. It works great, and there are a lot of folks in the community that use them and are willing to help out.