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Sensor build without BME8820

Am I able to build a sensor without the temp/humidity sensor and have it connected to the network? For instance, are the PM readings adjusted based on humidity at all? I want one indoors and already have a temp/humidity logger so don’t really want to buy another.

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The PM sensor needs info on the T/H of its direct environment because its readings are influences by it (heavily at high humidity). Possible corrections are not done implicitly so yes, you can measure without, bit if you want to make the necessary corrections you will need T/H related to the sensor.

And be honest: the cost can’t really be it for a BME820 (I assume 8820 is a typo?)

I feel the first sentence in the answer above gives the wrong impression.

Yes, you can build and connect a sensor with just PM but without humidity. That will work fine.

In case you want to develop your own correction based on other environmental data (such as temperature and humidity) you will of course need to add the respective sensors.

However, that correction will be your own, private experiment, as (I believe) the firmware currently offers no correction.

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BME280 actually :slight_smile:

Current IC shortage doesn’t help. Buying genuine BME280 is almost impossible right now. And the prices are 5x higher in the best case scenario.

I am not sure if this is a new topic but I am concerned about the accuracy of the BME280s. Living in the UK we do have high humidity but I have noticed one of my met sensors rarely reads below 100% humidity.This seems to be worse with the age of the sensor. Has anyone noticed this? Could there be a better met sensor ?

I have had several BME280 going into saturation. The least problematic went into the assemblies in the garden. I have more luck with the Sensirion SHT35.

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I have heard from somebody with a saturated sensor putting it in the oven for several hours on 100 degrees C. Then leaving it for several hours on room temperature in the living room to re-accomodate. That seemed to have restored the readings to correct levels.

If your sensor has become unusable you could give it a try.

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In order to restore the calibration state → section 3.3 in this document: