Good quality sensors for temperature, humidity and barometric pressure

Hi everyone :wink:
I’ve been asked to build a monitoring station for the above mentioned meteo conditions, by a friend that works in an “Environmental impact assessment” company.

They of course have loads of certified instrumentation, mostly for acoustic measurements (the arduino can’t compete with that, or actually I can’t), but they would also like some handier tools, still precise though, that they can bring on the field on the go.

So, instead of using the usual termistor, are there some accurate sensor for temperature, humidity and pressure, considering the measures would have to last for probably 24hrs? Also something stable as the measures have of course to be trustworthy.

I’m thinking of some commercial sensor, but I’ve just seen a termometer made by a infrared distance measurer.

I’m not really aiming for PCB as I don’t have the instruments for that, so some handy chips I had seen can’t be used

Read the datasheet for the BME280 for the exact specs of the accuracy of its sensors.

I have that sensor running now and it was easy to get it going. Quite sensitive too...just breathing in its direction will cause a change in humidity.

The only issue I am having is that the temperature reported by the BME280 is about 2 deg F higher than a set of 3 bare DS18B20 temperature sensors that are on the same breadboard with the BME280. The DS18B20's are all within a few 10ths of a degree of each other and are reading at 12-bit. I'm using the cactus.io BME280 library with a Mega 2560.

The issue of the temperature offset was also posted on the adafruit forum. The cactus.io library has a function to correct for temperature offset.