Been messing with using a BMP280 to control my chamber exhaust fan with the goal of maintaining a slight vacuum so all fumes are forced thru the exhaust. What I’m finding is the BMP280 just isn’t able to maintain a consistent reading. It tends to drift a lot and ends up reading vacuum levels that aren’t physically attainable, and you cant exactly re-zero the sensor unless you turn the fan off. I’ve tried lots of different filtering methods with no luck and have basically decided a true differential pressure sensor is what’s really needed.
Just wondering if anyone here has messed around with this and what they used.
I have been using BME* sensors for the last couple of months, BME680 specifically.
I did not try to make an exhaust fan, or something, but it normally shows adequate pressure data.
I did test it with a vacuum cleaner, and well, there is a pressure drop in the data.
I guess it should be able to show little difference from the fan, and from the datasheet, it can drift a little as the temperature increases.
Fabricate a slant tube manometer to measure chamber pressure.
Use a chamber fan with tach feedback blowing through the filter. Establish the fan PWM to get the desired pressure. Measure fan rpm at that PWM. If rpm goes high you have a leak, if fan speed drops time to change the filters.
You’d be fooled by the filter plugging at the same rate as leakage increases but an occasional glance at the manometer will solve that.