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Calibration - what are normal values?

General
#1

Dear fellow smartcitizens,

We’ve had our unit up and running for about a week in Stockholm, Sweden, you can easily see from the reading that it was kept indoors for a day or so we configured it and placed in a makeshift weatherproof box outside (changed the setting to outdoor at that time as well) - with enough holes in the bottom to get some circulation, but still protected from the weather Gods. Here it is: http://smartcitizen.me/devices/view/530

As you can see, the temperature is a bit higher than normal Swedish thermometers - have three digital ones around the building and they agree on 3 ±0.5 degrees lower temperature than the sensor device does.

Humidity is about 97%, the device offers a reading about 60%

Co is on 330 kOhm - how many ppms does this convert into? is it high or low?
No is about 17 kOhm - how many ppms is that?

As for sound, the lowest read value is truncated at 50 dB, right? I had 54 dB max while I was fiddling with the installation, but since then it seems stuck on 50.

best regards

Alex

#2

Hi Alex

We did some work in the calibration. Can you please upgrade the firmware to: https://github.com/fablabbcn/Smart-Citizen-Kit/releases/tag/v0.8.5? once you do it please let us know how it goes.

We might need some work done in that respect, but so far should be ok with this new firmware

Tomas

#3

I upgraded to 0.8.5 - but my temperatures are about 4-5 degrees below my Fluke instruments - which is confirmed by weather stations around me as well. Temperature should be around 17-18 - but SC shows 12.5

(For comparison : http://www.wunderground.com/global/stations/41217.html?MR=1) - I’m 5 km from AD Airport - and if you scroll all the way down - there are a few “user weather stations” in Khalifa A - that is between 1-6 km away. - all are pretty consistent in the about 18 degrees measurement. I would probably be about 1 degree lower as I’m right at the water.

I also noticed a few data points 27/01/2014 morning - are WAY off - 2000+ degrees for both mine and Swedish user’s hardware. (/view/530 and /view/591)

#4

Hi Kaz911,

Sorry for the late response.

Temperature and humidity peaks are already fixed. Something went wrong when coding. It happened to all of us. :slight_smile:

Calibration is a work in progress topic. All my sensors are also below the real temperature. We need to reformulate the algorithm. Also planning to set a calibration station. If your temperature is constant despite being unreal that would be helpful to know. Also other constants or variants.

Give us feedback, please!! :slight_smile:

All the best,
Aitor.

#5

For me it constants below 5 degree. I checked by put my digital thermometer near SCK.