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eNBeWe / MiCS6814-I2C-Library

Arduino library for my I2Ccontroller board for a MiCS-6814 based gas sensor as well as the Grove Multichannel Gas Sensor.
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Wrong measurements if NH3 is under 0.61 ppm #2

Open JMyrng opened 2 years ago

JMyrng commented 2 years ago

Hi there,

thank you for this good library for such a challenging sensor. (Does anyone know a better way to measure NH3?)

After warming up the Multichannel Sensor Board, the NH3 values are slowly dropping to 0.61 ppm, after that the value skyrockets to over 300 ppm.

Reading the resistance of the NH3 channel (getResistanceNH3), I see a value of just below 65536 for the realistic values. In my opinion, a stack overflow happens after that and the resistance values are very very low.

Anything I can do about that?

Edit: VVC is 5V

eNBeWe commented 2 years ago

I haven't put any work in this library for quite some time. I have to take a look at these values. Give me some time ... You are using the Groove Multichannel sensor at 5V, right?

eNBeWe commented 2 years ago

Just one thing I noticed: According to the sensor datasheet https://sgx.cdistore.com/datasheets/sgx/1143_datasheet%20mics-6814%20rev%208.pdf we are already below the detection range of the sensor.

That being said the values shouldn't jump due to some overflow.

JMyrng commented 2 years ago

You are using the Groove Multichannel sensor at 5V, right?

Yes, that's correct.

An additional info: the sensor was already on for quite some time. So maybe it's some kind of sensor degradation? I'll see if I can test a new sensor.