Carlos Alberto Laport de Miranda asked 5 years ago
Hi all,
I have two DHT22 sensor in the same room, one off them working with an ESP8266-12E (NODE-MCU) and the other working with an ESP8266-01. Both communicate with Node-RED via MQTT (No problems here). The “problem” is they show a 2,5 degrees C difference and more than 20% difference on the humidity readings. They use the same code to calculate and show the readings.
Are the DHT22 this innacurate ? Any thoughts are welcome.
Carlos…
Carlos Alberto Laport de Miranda answered 5 years ago
Continuing the tests, I mounted 4 other DHT22s with an ESP8266-NodeMCU.
With the following results:
The results are reasonable. The temperature readings within more or less 1% and all but one of the humidity readings being off the 2% tolerance.
Probably the DHT22 that was giving rogue readings is defective.
Sara Santos Staff answered 5 years ago
Hi.
Sometimes if the sensor is subjected to very high levels of humidity, it will take some time until it is able to detect low levels again.
However, I see that in your case, it is the other way around. So, probably there’s something wrong with that sensor.
Regards,
Sara
Carlos Alberto Laport de Miranda answered 5 years ago
Ok, I will change the rogue one with one of the 4 that gave “good” readings.
Thanks.