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Hypfer / esp8266-vindriktning-particle-sensor

Wifi MQTT Data Logging via an esp8266 for the Ikea VINDRIKTNING PM2.5 air quality sensor
Apache License 2.0
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Not an issue, low noise mod skews sensor results by ~50% #47

Open bvkrieken opened 2 years ago

bvkrieken commented 2 years ago

I've implemented the low noise mod and connected the fan permanently to the 3.3v pin of the Wemos D1. This does indeed reduce the fan noise significantly. But I do see a change in the sensor measurements though, they are about half as high compared to the results without the low noise mod.

2021-12-20 152800

My PM2,5 levels are to low to see whether this is an absolute reduction or a percentage reduction. Hopefully someone can give us a clear answer to that question.

bvkrieken commented 2 years ago

To find out what the real difference in measurements is between a normal sensor and the sensor with the low noise mod, I've connected both setups to my domotica system and physically placed them right next to each other. Since the atmospheric circumstances are identical it should give me the exact difference in measurements.

bvkrieken commented 2 years ago

After 24 hours of comparing the low noise modded sensor with the original sensor, I can conclude that the difference ratio between the two is ~1.82. So the 'real' value is the value of the low noise modded sensor times 1.82. comparison chart modded - not modded 2021-12-22 144950

boomvalt commented 1 year ago

This is actually a problem, because it will presumably affect the led indicator, potentially giving people a false sense of security.