Despite the fact I have used all the possible libraries I have found — the temperature is always +0.9-1.1 °C too high (compared with mercury thermometer, DS18B20 and home weather station).
I am aware of self-heating problem and using Force mode, currently like this:
I have 2 BME280 sensors. Both have +1 °C inaccuracy. I am OK with it (can be shifted on software level), but I am afraid that humidity sensor value depends on temperature, though humidity can be inaccurate as well (can't compare at the moment).
What's wrong with me or my sensor? How to get a correct temperature?
Please help. Thank you!
P.S.
Both 3.3 and 5 V power supply gives the same inaccurate temperature result.
The data sheet says that the typical (most usual) accuracy of the temperature signal of BME280 is +/-1oC. The data sheet has not mentioned anything in the max and min columns. Your BME280 exhibits an accuracy of +/-1.1oC. There is a 0.1o error/offset. Is it an error or a shift (offset)? -- can be verified by observing its responses at some other temperatures and comparing with the good one which you have. If it is an offset, it can be cancelled in the software as you have mentioned.
Moreover, for comparison reasons, we need a reference value. The reading of one BME280 can not be taken as a reference to evaluate the accuracy of another BME280. I have two temperature sensors LM35 and BME280 running at the same time. LM35 shows 29.54oC and BME280 shows 30.75oC. Which one is correct and accurate? To get the answer, I need another one which has been certified by the Testing Institution as a Reference Sensor (It is available at a very high cost.)
To measure the temperature and humidity in a room, there is no need to look for something better than the DS18B20 with the BME280. In a room, there are different temperature and humidity zones. They both are not the same for the whole room.
Yes, of course it does. No, of course it does not. Both are true. This is almost quantum mechanics
It measures the Relative Humidity, not how much mass or volume of water vapor is in the air.
When the temperature of one BME280 is +1°C offset and the temperature of another BME280 has an offset of -1°C, then I suppose that they both can have the same humidity. However the humidity is ±3% inaccurate. So this is all theory, in real life it does not matter.
blowing off some dust as i have the same problem but a bit more odd
at -18C it's correct (frezzer is set to -18C)
@ 5C it shows as 11C (fridge is set to 5C)
@ 24C it shows as 26C (messured with 2 ATC Semitec 104GT-2 sensors connected to 3D printer)
i'm trying to figure a metod to get temp closer to 30C and see if difference drops
and i will try and verify temps with a Mercury based temp gauge
but how would i correct/calbrate the readings so the "error" is more uniform?