“The sensors eventually arrived- they were late due to a Postal strike. The two sensors are connected to an RPi4 via a multiplexer. After testing over 5 days I am very impressed with their accuracy. They have an offset of 1mBar when compared to our high precision, calibrated Barometer. The offset appears consistent over time and temperature variation. These were simple to get into service due to the circuit Python code supplied by Adafruit. I will be temperature cycling both sensors over 10 days to get a feel for any temperature effects. If successful the sensors will be used to indirectly monitor water levels in a column.”
“Excellent little sensor. A couple of points that may help others - This measures absolute pressure, not gauge pressure, so in free air it will read about 15psi, so another 10psi to play with - unless of course you are measuring suction.
If you are using it to measure system pressure and you need to measure small changes - in my case the depth of water in a canal boat tank (about 2ft high), then unless you can take an atmospheric pressure reading first, the changes in atmospheric pressure due to weather and altitude will give a very inaccurate reading. To get around this you will need a second barometric sensor to give you a 'zero' reading to subtract from your system pressure sensor.”
